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The information in this preliminary prospectus supplement is not complete and may be changed. A registration statement relating to these securities has been filed with the Securities and Exchange Commission and is effective. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities, and we are not soliciting offers to buy these securities in any state or other jurisdiction where the offer or sale is not permitted.
 Filed Pursuant to Rule 424(b)(5)
 Registration No. 333-249925
Subject to completion, dated February 3, 2021
Preliminary prospectus supplement
(To prospectus dated November 6, 2020)
$200,000,000
[MISSING IMAGE: lg_quantlexington-4c.jpg]
Common stock
We are offering $200,000,000 of shares of our common stock.
Our common stock is listed on The Nasdaq Global Market under the symbol “QTRX.” The last reported sale price of our common stock on The Nasdaq Global Market on February 2, 2021 was $74.62 per share.
Per share
Total
Public offering price
$       $      
Underwriting discounts and commissions(1)
$       $      
Proceeds to Quanterix Corporation, before expenses
$       $      
(1)
We refer you to “Underwriting” beginning on page S-22 of this prospectus supplement for additional information regarding total underwriting compensation.
The underwriters may also exercise their option to purchase up to $30,000,000 of additional shares of our common stock from us, at the public offering price, less the underwriting discount, for 30 days after the date of this prospectus supplement.
Investing in our common stock involves a high degree of risk. Please read “Risk factors” beginning on page S-11 of this prospectus supplement and in the documents that are incorporated by reference into this prospectus supplement.
Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense.
Delivery of the shares of common stock will be made on or about February   , 2021.
Joint Bookrunning Managers
Goldman Sachs & Co. LLC
SVB Leerink
Cowen
Lead Manager
Canaccord Genuity
Prospectus supplement dated February   , 2021.

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About this prospectus supplement
This prospectus supplement and the accompanying prospectus are part of a “shelf” registration statement on Form S-3ASR (File No. 333-249925) that we initially filed with the Securities and Exchange Commission, or SEC, on November 6, 2020, and that became effective automatically upon filing. This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this common stock offering and also adds to and updates information contained in the accompanying prospectus and the documents incorporated by reference herein. The second part, the accompanying prospectus, including the documents incorporated by reference therein, provides more general information. Generally, when we refer to this prospectus, we are referring to both parts of this document combined. To the extent there is a conflict between the information contained in this prospectus supplement and the information contained in the accompanying prospectus or any document incorporated by reference therein filed prior to the date of this prospectus supplement, you should rely on the information in this prospectus supplement; provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date — for example, a document incorporated by reference in the accompanying prospectus — the statement in the document having the later date modifies or supersedes the earlier statement.
We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference herein were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.
You should rely only on the information contained in this prospectus supplement or the accompanying prospectus, or incorporated by reference herein. We have not authorized, and the underwriters have not authorized, anyone to provide you with information that is different. The information contained in this prospectus supplement or the accompanying prospectus, or incorporated by reference herein is accurate only as of the respective dates thereof, regardless of the time of delivery of this prospectus supplement and the accompanying prospectus or of any sale of our common stock. It is important for you to read and consider all information contained in this prospectus supplement and the accompanying prospectus, including the documents incorporated by reference herein and therein, in making your investment decision. You should also read and consider the information in the documents to which we have referred you in the sections entitled “Where you can find more information” and “Incorporation by reference” in this prospectus supplement and in the sections entitled “Where you can find more information” and “Incorporation of documents by reference” in the accompanying prospectus, respectively.
We are offering to sell, and seeking offers to buy, shares of our common stock only in jurisdictions where offers and sales are permitted. The distribution of this prospectus supplement and the accompanying prospectus and the offering of the common stock in certain jurisdictions may be restricted by law. Persons outside the United States who come into possession of this prospectus supplement and the accompanying prospectus must inform themselves about, and observe any restrictions relating to, the offering of the common stock and the distribution of this prospectus supplement and the accompanying prospectus outside the United States. This prospectus supplement and the accompanying prospectus do not constitute, and may not be used in connection with, an offer to sell, or a solicitation of an offer to buy, any securities offered by this prospectus supplement and the accompanying prospectus by any person in any jurisdiction in which it is unlawful for such person to make such an offer or solicitation.
Unless the context otherwise requires, all references in this prospectus supplement and the accompanying prospectus to “Quanterix,” “QTRX,” “the Company,” “we,” “us,” “our” and similar terms refer to Quanterix Corporation and our subsidiaries.
 
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Prospectus supplement summary
This summary highlights information contained elsewhere or incorporated by reference in this prospectus supplement and the accompanying prospectus. This summary does not contain all of the information that you should consider before deciding to invest in our common stock. You should read this entire prospectus supplement and the accompanying prospectus carefully, including the “Risk factors” section contained in this prospectus supplement, our consolidated financial statements and the related notes thereto and the other documents and information incorporated by reference in this prospectus supplement and the accompanying prospectus.
Overview
We are a life sciences company that has developed next generation, ultra-sensitive digital immunoassay platforms that advance precision health for life sciences research and diagnostics. Our platforms are based on our proprietary digital “Simoa” detection technology. Our Simoa bead-based and planar array platforms enable customers to reliably detect protein biomarkers in extremely low concentrations in blood, serum and other fluids that, in many cases, are undetectable using conventional, analog immunoassay technologies, and also allow researchers to define and validate the function of novel protein biomarkers that are only present in very low concentrations and have been discovered using technologies such as mass spectrometry. These capabilities provide our customers with insight into the role of protein biomarkers in human health that has not been possible with other existing technologies and enable researchers to unlock unique insights into the continuum between health and disease. We believe this greater insight will enable the development of novel therapies and diagnostics and facilitate a paradigm shift in healthcare from an emphasis on treatment to a focus on earlier detection, monitoring, prognosis and, ultimately, prevention. We are currently focusing on protein detection, which we believe is an area of significant unmet need and where we have significant competitive advantages. However, in addition to enabling new applications and insights in protein analysis, our Simoa platforms have also demonstrated applicability across other testing applications, including detection of nucleic acids and small molecules.
We believe that our Simoa platforms are the most sensitive commercially available protein detection platforms and significantly advance enzyme-linked immunosorbent assay, or ELISA, technology, which has been the industry standard for protein detection for over 40 years. Proteins are complex molecules that are required for the structure, function and regulation of the body’s tissues and organs, and are the functional units that carry out specific tasks in every cell. The human body contains approximately 20,000 genes, each of which can produce multiple proteins. It is estimated that these 20,000 genes can produce over 100,000 different proteins, approximately 10,500 of which are known to be secreted in blood. Accordingly, while research on nucleic acids provides valuable information about the role of genes in health and disease, proteins are more prevalent and, we believe, more relevant to a precise understanding of the nuanced continuum between health and disease. Protein measurement goes beyond genetic predisposition, reflecting the impact of a range of influences on health, including environmental factors and lifestyle, providing deeper and more relevant insight into what is happening in a person’s body in real time.
Researchers and clinicians rely extensively on protein biomarkers for use as research and clinical tools. However, normal physiological levels of many proteins are not detectable using conventional, analog immunoassay technologies, and many of these technologies can only detect proteins once they have reached levels that reflect more advanced disease or injury. For many other low abundance proteins, these technologies cannot detect proteins even at disease- or injury-elevated levels. We believe that Simoa’s sensitivity offers a new way to monitor healthy individuals and detect proteins associated with nascent disease or injury early in the disease cascade, which holds the key to intervention before disease or injury has advanced to the point where more significant clinical signs and symptoms have appeared.
Our Simoa platforms have achieved significant scientific validation and commercial adoption. Simoa technology has been cited in more than 1,100 scientific publications in areas of high unmet medical need and research interest such as neurology, oncology, cardiology, infectious disease and
 
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inflammation. Our growing customer base is comprised of approximately 950 customers across our end markets, and includes 20 of the 20 largest biopharmaceutical companies.
Our products and services
Our proprietary Simoa technology is based on traditional ELISA technology, which has been the most widely used method of detection of proteins for over 40 years. Given our target customers’ familiarity with the core ELISA technology, we believe this offers us a significant competitive advantage. Our Simoa bead-based platform differs, however, from conventional ELISA in its ability to trap single molecules in tiny microwells, 40 trillionths of a milliliter, that are 2.5 billion times smaller than traditional ELISA wells, allowing for an analysis and digital readout of each individual molecule, which is not possible with conventional ELISA technology. This ability is the key to our bead-based technology’s unprecedented sensitivity. In January 2018, we acquired Aushon BioSystems, Inc., or Aushon, and its proprietary sensitive planar array detection technology. Leveraging our proprietary sophisticated Simoa image analysis and data analysis algorithms, we further refined this planar array technology to provide the same Simoa sensitivity found in our Simoa bead-based platform. We currently offer the following three Simoa instruments, which we believe are the most sensitive protein detection platforms commercially available today:

HD-X:   We commercially launched our HD-X instrument in the second half of 2019. The HD-X is an upgraded version of the Simoa HD-1 (which was launched in January 2014) that was designed to deliver significant productivity and operational efficiency improvements, as well as greater user flexibility. The HD-X is based on our bead-based technology, and assays run on the HD-X are fully automated. We believe the full automation of the HD-X provides us with an additional significant competitive advantage with biopharmaceutical customers.

SR-X:   We commercially launched our SR-X instrument in December 2017. The SR-X utilizes the same Simoa bead-based technology and assay kits as the HD-1 in a compact benchtop form with a lower price point, more flexible assay preparation, and a wider range of potential applications.

SP-X:   We commercially launched our SP-X instrument in April 2019. The SP-X is based on our planar array technology, which allows for significantly greater multiplexing capabilities, and is, we believe, ideal for oncology and immunology applications.
The current menu of approximately 86 analyte-specific single-plex and multi-plex bead-based assay kits includes assays for biomarkers in the areas of neurology, infectious disease, immunology, oncology and cardiology for both human and mouse samples. The current menu of Simoa planar array reagent kits includes approximately 100 biomarkers ranging from 1-10 analytes per assay in the areas of immunology and oncology research. We intend to continue to increase the number of Simoa biomarker assays across our platforms. In addition, both the bead-based platform and the planar array platform allow ease and flexibility in assay design, enabling our customers to develop their own in-house assays, called “homebrew” assays.
We also provide contract research services for customers through our CLIA-certified Accelerator Laboratory. The Accelerator Laboratory provides customers with access to Simoa technology, and supports multiple projects and services, including sample testing, homebrew assay development and custom assay development. To date, we have completed over 1,300 projects for approximately 360 customers from all over the world using our Simoa platforms. In addition to being an important source of revenue, we have also found the Accelerator Laboratory to be a significant catalyst for placing additional instruments, as a number of customers for whom we have provided contract research services have subsequently purchased an instrument from us.
In addition, in August 2019, we completed the acquisition of UmanDiagnostics AB, or Uman, a company located in Umeå, Sweden, that supplies neurofilament light (Nf-L) antibodies and Nf-L ELISA kits. Uman’s Nf-L antibodies are widely recognized by researchers and biopharmaceutical and diagnostics companies world-wide as the premier solution for the detection of Nf-L to advance the development of therapeutics and diagnostics for neurodegenerative conditions. The Uman acquisition secures the Nf-L antibody supply critical to our industry leading ultrasensitive Simoa Nf-L assays and services, provides
 
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us with additional revenue opportunities via the sale of the Nf-L antibodies and Nf-L ELISA kits, and positions us to capitalize on significant growth opportunities with Nf-L applications in Alzheimer’s disease, multiple sclerosis, and other neurodegenerative conditions.
In view of the COVID-19 pandemic, in the second quarter of 2020 we adjusted our operations to expand capacity in our Accelerator Laboratory to support customers whose operations have been disrupted and to sustain their clinical trials. We also determined that our cytokine assay technology could provide researchers with important and differentiated tools to study disease progression, cytokine release syndrome, and patient-treatment response in the fight against COVID-19, and began developing a SARS-CoV-2 semi-quantitative IgG assay and a SARS-CoV-2 antigen detection assay and prototyping a high-definition SARS-CoV-2 assay.
In December 2020, the U.S. Food and Drug Administration, or FDA, issued an Emergency Use Authorization, or EUA, for our Simoa Semi-Quantitative SARS-CoV-2 IgG Antibody Test that is run on our HD-X instrument. This test targets antibodies that are directed against the region of the novel coronavirus known as the spike protein. The spike protein contains multiple subunits which together mediate entry of the virus into human cells, and for this reason many candidate and authorized COVID-19 vaccines are designed to elicit an antibody response to the spike protein. Accordingly, we believe that this test may be useful for measuring the antibody response to vaccine therapy. The assay may also be used for measurement of IgG antibodies in patients suspected of previous infection or recent SARS-CoV-2 exposure. The test provides a numerical result representing the concentration of antibodies from 0.21 to 250 mg/mL. In clinical studies, the test demonstrated a 100 percent positive percent agreement (sensitivity) and 99.2 percent negative percent agreement (specificity) 15 or more days following a positive PCR test.
In January 2021, the FDA issued an EUA for our Simoa SARS-CoV-2 N Protein Antigen Test that is also run on our HD-X instrument. This test detects the presence of the SARS-CoV-2 virus nucleocapsid protein (or N protein) which is known to be elevated in respiratory fluids during the initial acute phase of the infection. We believe that direct detection of antigen proteins from the virus may be a more meaningful measure of infection status than detection of RNA by rRT-PCR because genetic material can linger even after the virus has left the body, resulting in increased risk of false positives. In clinical studies, this test demonstrated a sensitivity of 97.7% and specificity of 100% up to 14 days following onset of symptoms. Under the current EUA, the test is intended for use with nasopharyngeal (NP) samples in individuals suspected of COVID-19 infection by their healthcare providers. We currently intend to pursue authorization for additional sample types, including nasal swabs, saliva, and capillary dried blood obtained from a fingerstick. Preliminary clinical research studies suggest the viral antigen may be readily detectable in asymptomatic and pre-symptomatic patients, and we are exploring extending the test to screening applications, home-based sample collection and pooling to enable larger scale testing.
In September 2020, we entered into a workplan 2 (WP2) contract with the National Institute of Health, or NIH, under the Rapid Acceleration of Diagnostics, or RADx, program. This contract, which has a total award value of $18.2 million, is intended to accelerate the continued development, scale-up and deployment of our novel SARS-CoV-2 antigen test. Initial early feasibility of this test was funded in part through the RADx workplan 1 (WP1) award we were granted in June 2020. The WP2 contract supports clinical validation of the test in support of the EUA submissions with the FDA, and provides funding to expand assay kit manufacturing capacity and commercial deployment readiness. Contract funding is subject to achievement of pre-defined milestones and the contract period runs through September 2021.
In September 2020, we entered into a Non-exclusive License Agreement with Abbott Laboratories. Pursuant to the terms of this agreement, we granted Abbott a non-exclusive, worldwide, royalty-bearing license, without the right to sublicense, under our bead-based single molecule detection patents in the field of in vitro diagnostics. Abbott paid us an initial license fee of $10.0 million in connection with the execution of the agreement. Abbott has also agreed to pay us milestone fees subject to the achievement by Abbott of certain development, regulatory and commercialization milestones and low single digit royalties on net sales of licensed products.
 
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We sell our instruments, consumables and services to the life science, pharmaceutical and diagnostics industries through a direct sales force and support organizations in North America and Europe, and through distributors or sales agents in other select markets. In addition, Uman sells Nf-L antibodies and Nf-L ELISA kits directly, and in conjunction with a distributor worldwide (excluding certain Nordic countries). We have an extensive base of customers in world class academic and governmental research institutions, as well as pharmaceutical, biotechnology and contract research companies, using our technology to gather information to better understand human health.
Our market opportunities
Our Simoa platforms have applications across the life science research, diagnostics and precision health screening markets. Our initial target market has been the life science research market, in particular neurology as well as immunology and oncology. According to estimates in a custom market research report by an independent third-party research firm, which was commissioned by us and was issued in January 2021 (the Third-Party Research Report), we believe that our pre-COVID addressable neurology, immunology and oncology life science research market was approximately $1 billion per year. We believe our recent EUA approvals will allow us to participate in the COVID testing market, with an addressable market estimated at approximately $12 billion. These approvals also expand our life science research market focus into COVID-19, which we estimate has currently addressable potential of $0.2 billion. As we further expand our life science research focus in other areas of immunology, oncology and other therapeutic areas, coupled with growing adoption of decentralized clinical trials, the life science research addressable market is expected to expand to approximately $7 billion. As our customers continue to gain experience with our proprietary Simoa technology, we believe the opportunity to access markets beyond research, such as diagnostics and precision health screening, will be significant. The Third-Party Research Report also estimates that the diagnostic and precision health screening markets have the potential to reach an aggregate of approximately$55 billion per year, with neurology diagnostics estimated at approximately $18 billion, proteomic liquid biopsy estimated at approximately $20 billion, COVID at approximately $12 billion, and precision health screening estimated at approximately $5 billion.
Life science research
Our initial target market has been the large and growing life science research market. We believe our Simoa platforms are well-positioned to capture a significant share of this market because of superior sensitivity, automated workflow capabilities, multiplexing and the ability to work with a broader range of sample types. By substantially lowering the limit of detection of protein biomarkers, we believe that Simoa is penetrating the existing market for protein analysis and holds potential to significantly grow the life science research market as researchers expand their research into the diseases associated with the thousands of proteins that were previously undetectable. Simoa also enables earlier detection of the proteins that are currently detectable by other technologies only after they have reached levels that reflect more advanced disease or injury. As an indication of the market’s acceptance of our technology, biopharmaceutical researchers are also integrating our platforms into drug development protocols to more efficiently and effectively develop drugs. In addition to enabling new applications and insights in protein analysis, our Simoa bead-based technology can be used to detect other analytes, such as nucleic acids and small molecules, which expands our market opportunity. We believe that this technology has the potential to ultimately provide the same sensitivity as polymerase chain reaction, or PCR, which is the most commonly used technology for nucleic acid detection, without the distortion and bias issues associated with amplification used in PCR.
Diagnostics
We believe the diagnostic market represents a significant commercial opportunity for our Simoa technology as well. We believe existing diagnostics can be improved by Simoa’s sensitivity to enable earlier detection of diseases and injuries, and that new diagnostics may be developed using protein biomarkers that are not detectable using conventional, analog immunoassay technologies but are detectable using Simoa. We also believe that the ultra-sensitive protein detection provided by Simoa can enable the development of a new category of non-invasive diagnostic tests and tools based on blood,
 
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serum, saliva and other fluids that have the potential to replace current more invasive, expensive and inconvenient diagnostic methods, including spinal tap, diagnostic imaging and biopsy.
Simoa technology also has significant potential in the emerging field of companion diagnostics. Drug developers can use Simoa to stratify patients into categories, enabling selection of those patients for whom a drug is expected to be most effective and safe. Not only does Simoa have the potential to be used to develop companion diagnostics to stratify patients in clinical trials and for treatment, but Simoa’s sensitivity may also enable the development of companion diagnostics based on protein biomarkers that can regularly monitor whether an approved drug is having the desired biological effect, enabling doctors to quickly and efficiently adjust the course of treatment as appropriate.
In early 2020, we determined that our cytokine assay technology had the potential to provide researchers with important and differentiated tools to study disease progression, cytokine release syndrome, and patient-treatment response in the fight against COVID-19, and we began developing a SARS-COV-2 semi-quantitative IgG assay and a SARS-CoV-2 antigen detection assay and prototyping a high-definition SARS-COV-2 assay. In December 2020, the FDA issued an EUA for our Simoa Semi-Quantitative SARS-CoV-2 IgG Antibody Test, and in January 2021, the FDA issued an EUA for our Simoa SARS-CoV-2 N Protein Antigen Test, each of which is run on our HD-X instrument.
Precision health screening
The ability of our Simoa platforms to detect and quantify normal physiological levels of proteins in low abundance that are undetectable using conventional, analog immunoassay technologies may enable our technology to be used to monitor protein biomarker levels of seemingly healthy, asymptomatic people, and potentially to signal and provide earlier detection of the onset of disease. We believe there is the potential for a number of neurological, cardiovascular, oncologic and other protein biomarkers associated with disease to be measured with a simple blood draw on a regular, ongoing basis as part of a patient’s routine health screening, and for those results to be compared periodically with baseline measurements to predict or detect the early onset of disease, prior to the appearance of symptoms.
Simoa products sold or used in the diagnostics and precision health screening markets will be subject to regulation by the U.S. Food and Drug Administration, or FDA, or comparable international agencies, including requirements for regulatory clearance or approval of such products before they can be marketed. See Item 1A, “Risk Factors — Risks Related to Governmental Regulation and Diagnostic Product Reimbursement” and “Business — Government Regulation” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2019 for a more detailed discussion regarding the regulatory approvals that may be required.
We have focused the application of our Simoa technology on areas of high growth and high unmet need and where existing platforms have significant shortcomings that our technology addresses. In particular, we have focused on the following areas: neurology, oncology, cardiology, infectious disease and inflammation.
Our strategy
Our goal is to enable new research into biomarkers to allow greater insight into their role in human health in ways that have not been possible with any other current research and diagnostic technology. We believe this greater insight will facilitate a paradigm shift in healthcare from an emphasis on treatment to a focus on earlier detection, monitoring, prognosis and, ultimately, prevention.
In order to achieve this, our strategies include the following:

Focus on the highly attractive, expanding market for protein detection and analysis;

Continue to drive adoption of our Simoa technology in the life science research market in the near-term, and the diagnostics and precision health screening markets in the long-term;

Leverage the growing importance of Nf-L as a biomarker to advance the development of therapeutics and diagnostics for neurodegenerative conditions;
 
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Grow into new markets organically with our customers and through strategic collaborations; and

Grow through strategic acquisitions.
Recent developments
The following information reflects preliminary financial information and results of operations for the quarter and year ended December 31, 2020, based on currently available information. The estimated unaudited financial results as of and for the quarter and full fiscal year ended December 31, 2020 presented below are preliminary and are subject to completion of our quarter-end and year-end closing procedures and further financial review. These procedures often result in changes to accounts. Our actual results may differ from these estimates as a result of the completion of our quarter-end and year-end closing procedures, review adjustments and other developments that may arise between now and the time our financial results for the fourth quarter and year are finalized. We undertake no obligation to update or supplement the information provided below until we release our financial statements for the quarter and year ended December 31, 2020.
The preliminary financial data included in this prospectus supplement has been prepared by, and is the responsibility of, our management. Ernst & Young LLP has not audited, reviewed, compiled, or applied agreed-upon procedures with respect to the preliminary financial information and results of operations. Accordingly, Ernst & Young LLP does not express an opinion or any other form of assurance with respect thereto.
We estimate that GAAP revenue for the three months ended December 31, 2020 will be between $24 million and $26 million, compared with $15.9 million in the fourth quarter of 2019. Excluding approximately $4 million in revenue from the RADx contract, we estimate non-GAAP revenue for the three months ended December 31, 2020 will be between $20 million and $22 million, an increase of approximately 32% based on the midpoint of the range compared with GAAP revenue in the fourth quarter of 2019. We estimate that revenue for the year ended December 31, 2020 will be between $84 million and $86 million, compared with $56.7 million in 2019. Excluding approximately $5.9 million in revenue from the RADx contract and $11.2 million in revenue from the Abbott license agreement, we estimate non-GAAP revenue for the year ended December 31, 2020 will be between $67 million and $69 million, an increase of approximately 20% based on the midpoint of the range compared with 2019 GAAP revenue.
We estimate that unrestricted cash, cash equivalents and marketable securities were approximately $181.5 million as of December 31, 2020.
We have accounted for the RADx contract milestone payments under IAS 20, Accounting for Government Grants and Disclosure of Government Assistance, or IAS 20. Under IAS 20, we expect that approximately 50% of the total RADx contract milestone payments (or approximately $9 million) will be recognized as grant revenue, of which approximately $4 million was recognized as grant revenue in 2020. We expect that the remainder will be recognized in 2021. We expect that approximately $9 million of the RADx contract milestone payments will relate to reimbursement for the purchase of property and equipment and will be recorded as a reduction in the carrying value of such assets and will have no grant revenue associated with them in the profit and loss statement.
To supplement our financial revenue presented on a GAAP basis, we have provided information on non-GAAP revenue. Management uses this non-GAAP measure to evaluate our operating performance in a manner that allows for meaningful period-to-period comparison and analysis of trends in our business. Management believes that this measure is important in comparing current results with prior period results and is useful to investors and financial analysts in assessing our operating performance. The non-GAAP financial information presented here should be considered in conjunction with, and not as a substitute for, the financial information presented in accordance with GAAP.
Risks relating to our business
We are a life sciences company, and our business and ability to execute our business strategy are subject to a number of significant risks of which you should be aware before you decide to buy shares of our common stock. Among these important risks are the following:
 
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We have incurred annual losses since we were formed and expect to incur losses in the future. We cannot be certain that we will achieve or sustain profitability;

Our quarterly and annual operating results and cash flows have fluctuated in the past and might continue to fluctuate, causing the value of our common stock to decline substantially;

We are an early, commercial-stage company and have a limited commercial history, which may make it difficult to evaluate our current business and predict our future performance;

If our products fail to achieve and sustain sufficient market acceptance, our revenue will be adversely affected;

Sales of our assay for the neurological biomarker Nf-L have become increasingly important to our business, and any significant decrease in sales of that assay could have a material adverse effect on our business;

We are subject to extensive regulatory requirements in connection with the EUAs that we have received from the FDA for our COVID-19 antibody and antigen tests, and if we fail to comply with these requirements, or if the FDA otherwise determines that the conditions no longer warrant such authorization, we will be unable to market these products pursuant to this authorization and our business may be harmed.

The termination of an EUA, the failure of our tests to gain market acceptance or our inability to match advances in competing products for COVID-19 could adversely impact our business.

Epidemic diseases, such as COVID-19, could negatively affect various aspects of our business, make it more difficult to meet our obligations to our customers, and result in reduced demand from our customers, which could have a material adverse effect on our business, financial condition, results of operations, or cash flows;

Release of the remaining funding under the contract with NIH under the RADx program is based on the achievement of certain milestones, and there is no assurance that we can meet all the milestones on a timely basis, if at all.

Our long-term results depend upon our ability to improve existing products and introduce and market new products successfully;

Undetected errors or defects in our products could harm our reputation, decrease market acceptance of our products or expose us to product liability claims;

We may seek to enter into strategic collaborations and licensing arrangements with third parties, but we may not be successful in establishing or maintaining such arrangements;

We expect to generate a substantial portion of our revenue internationally in the future and can become further subject to various risks relating to our international activities, which could adversely affect our business, operating results and financial condition;

We have limited experience in marketing and selling our products, and if we are unable to successfully commercialize our products, our business and operating results will be adversely affected;

We may experience manufacturing problems or delays, or backlogs in deliveries, that could limit the growth of our revenue or increase our losses;

We rely on a single contract manufacturer to manufacture and supply our Simoa HD instruments and rely on a different single contract manufacturer to manufacture and supply our Simoa SR-X. If either of these manufacturers should fail or not perform satisfactorily, our ability to supply these instruments would be negatively and adversely affected;

If the FDA determines that our products are medical devices or if we seek to market our products for clinical diagnostic or health screening use, we will be required to obtain regulatory clearance(s) or approval(s) and may be required to cease or limit sales of our then marketed products, which could materially and adversely affect our business, financial condition and results of operations. Any such regulatory process would be expensive, time-consuming and uncertain both in timing and in outcome;
 
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If we do not comply with governmental regulations applicable to our CLIA-certified laboratory, we may not be able to continue our operations;

If we are unable to protect our intellectual property, it may reduce our ability to maintain any technological or competitive advantage over our competitors and potential competitors, and our business may be harmed;

The measures that we use to protect the security of our intellectual property and other proprietary rights may not be adequate, which could result in the loss of legal protection for, and thereby diminish the value of, such intellectual property and other rights;

If we or any of our partners are sued for infringing intellectual property rights of third parties, it would be costly and time-consuming, and an unfavorable outcome in that litigation could have a material adverse effect on our business;

If you purchase shares of common stock in this offering, you will suffer immediate dilution of your investment; and

Our management will have broad discretion over the use of the net proceeds from this offering, and you may not agree with how we use the proceeds and the proceeds may not be invested successfully.
For additional information about the risks we face, please see the information contained in or incorporated by reference under “Risk factors” on page S-11 of this prospectus supplement and page 4 of the accompanying prospectus.
Corporate information
We were originally incorporated in the State of Delaware in April 2007 under the name “Digital Genomics, Inc.” In August 2007, we changed our name to “Quanterix Corporation.” Our principal executive offices are located at 900 Middlesex Turnpike, Billerica, Massachusetts 01821, and our telephone number is (617) 301-9400. We maintain a website at http://www.quanterix.com, to which we regularly post copies of our press releases as well as additional information about us. The information contained on, or that can be accessed through, our website is not a part of this prospectus. We have included our website address in this prospectus solely as an inactive textual reference.
Our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and all amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, are available free of charge through the investor relations page of our website as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC.
All brand names or trademarks appearing in this prospectus supplement and the accompanying prospectus are the property of their respective holders. Use or display by us of other parties’ trademarks, trade dress, or products in this prospectus supplement and the accompanying prospectus is not intended to, and does not, imply a relationship with, or endorsements or sponsorship of, us by the trademark or trade dress owners.
 
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The offering
Common stock offered by us pursuant to this prospectus supplement
$200,000,000 of shares of our common stock
Common stock estimated to be outstanding immediately after this offering
          shares
Option to purchase additional shares
We have granted the underwriters an option for a period of up to 30 days to purchase up to          additional shares of common stock at the offering price, less the underwriting discount.
Use of proceeds
We estimate that the net proceeds from this offering will be approximately $      million, or approximately $      million if the underwriters exercise their option to purchase additional shares in full, after deducting the underwriting discounts and commissions and estimated offering expenses payable by us.
We currently intend to use the net proceeds from this offering to (1) to expand our life sciences commercial operations to grow and support the installed base of our products among life sciences customers in the United States and internationally; (2) to improve and update our Simoa technology and instruments and to develop additional assays; (3) to potentially pursue regulatory approvals or clearances to develop instruments, assay kits and consumables in areas outside of life science research and, subject to receipt of such necessary regulatory approvals or clearances, to develop such instruments, assay kits and consumables; (4) to potentially pursue acquisitions or other business development opportunities; and (5) for working capital and other general corporate purposes, including, but not limited to, capital expenditures, investments, and collaborations. See the section entitled “Use of proceeds” on page S-15 of this prospectus supplement.
Risk factors
An investment in our common stock involves a high degree of risk. See the information contained in or incorporated by reference under “Risk factors” on page S-11 of this prospectus supplement, as well as the other information included in or incorporated by reference in this prospectus supplement and the accompanying prospectus.
Nasdaq Global Market
Symbol
Our common stock is listed on The Nasdaq Global Market under the symbol “QTRX.”
The number of shares of our common stock to be outstanding immediately after this offering is based on an aggregate of 31,836,339 shares of common stock outstanding as of December 31, 2020 and excludes:

2,494,045 shares of our common stock issuable upon the exercise of stock options outstanding as of December 31, 2020, at a weighted average exercise price of $17.73 per share, of which 1,514,576 shares were vested as of such date;

478,581 shares of our common stock issuable upon the vesting of restricted stock units outstanding as of December 31, 2020;
 
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10,000 shares of our common stock issuable upon the exercise of warrants outstanding as of December 31, 2020, at an exercise price of $21.00 per share;

710,839 shares of common stock reserved for future issuance under the 2017 Employee, Director and Consultant Equity Incentive Plan as of December 31, 2020, which does not include an additional 1,273,453 shares of common stock added to this plan on January 1, 2021 pursuant to an evergreen provision; and

848,269 shares of common stock reserved for future issuance under the 2017 Employee Stock Purchase Plan as of December 31, 2020, which does not include an additional 318,363 shares of common stock added to this plan on January 1, 2021 pursuant to an evergreen provision.
Except as otherwise indicated, all information in this prospectus supplement assumes no exercise by the underwriters of their option to purchase additional shares of our common stock.
 
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Risk factors
Investing in our common stock involves a high degree of risk and uncertainty. In addition to the risks and uncertainties discussed under the section captioned “Risk Factors” contained in our Annual Report on Form 10-K for the fiscal year ended December 31, 2019 and in our subsequent filings with the SEC incorporated by reference in this prospectus, including our Quarterly Reports on Form 10-Q for the quarter ended September 30, 2020, together with the other information included in this prospectus and documents incorporated by reference in this prospectus, you should read in their entirety and carefully consider the risks described below before making an investment decision with respect to this offering. Any of the following risks could have a material adverse effect on our business, financial condition, results of operations or cash flow. This could cause the trading price of our common stock to decline, which could cause you to lose all or part of your investment.
Risks related to our EUAs
We are subject to extensive regulatory requirements in connection with the EUAs that we have received from the FDA for our COVID-19 antibody and antigen tests. If we fail to comply with these requirements, or if the FDA otherwise determines that the conditions no longer warrant such authorization, we will be unable to market these products pursuant to this authorization and our business may be harmed.
We have received EUAs from the FDA authorizing us to market our Simoa Semi-Quantitative SARS-CoV-2 IgG Antibody Test and our Simoa SARS-CoV-2 N Protein Antigen Test, each of which is run on our HD-X instrument. These EUAs allow us to market and sell these products without the need to obtain premarket clearance or approval under the FDA’s standard review pathways for the duration of the COVID-19 public health emergency. The FDA has also established certain conditions which must be met in order to maintain authorization under these EUAs. The requirements can be unclear and are subject to change.
The FDA has the authority to issue an EUA during a public health emergency if it determines, based on the totality of the scientific evidence, that it is reasonable to believe that the product may be effective, that the known and potential benefits of a product outweigh the known and potential risks, that there is no adequate, approved and available alternative, and if certain other regulatory criteria are met. These standards for marketing authorization are lower than if the FDA had reviewed these tests under its traditional marketing authorization pathways, and we cannot assure you that our tests would be cleared or approved under those more extensive clearance and approval standards. Moreover, the FDA’s policies regarding EUAs can change unexpectedly, and the FDA may revoke an EUA when it determines that the underlying health emergency no longer exists or warrants such authorization or if problems are identified with the authorized product. We cannot predict how long our authorizations will remain in place. FDA policies regarding diagnostic tests, therapies and other products used to diagnose, treat or mitigate COVID-19 remain in flux as the FDA responds to new and evolving public health information and clinical evidence. Changes to FDA regulations or requirements could require changes to our authorized tests, necessitate additional measures or make it impractical or impossible for us to market our tests at all.
In addition, even though we have received these EUAs, these tests may not gain broad market acceptance among customers, including physicians, healthcare payors, users and others in the medical community. The commercial success of our COVID-19 tests will initially be dependent upon physicians and healthcare providers adopting our test kits, which will be informed, in part, by the convenience and accuracy of our tests. Furthermore, the COVID-19 diagnostic testing market is susceptible to rapid technological developments and we may not be able to match new technological advances, which might render our COVID-19 test kits uncompetitive or obsolete. If we are unable to match technological improvements in competitive products or effectively respond to the needs of our customers and users, the demand for our COVID-19 test kits could be reduced.
The termination of an EUA, the failure of our tests to gain market acceptance or our inability to match advances in competing products could adversely impact our business.
 
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Risks related to this offering
If you purchase shares of common stock in this offering, you will suffer immediate dilution of your investment.
The public offering price of our common stock is substantially higher than the net tangible book value per share of our common stock. Therefore, if you purchase shares of our common stock in this offering, you will pay a price per share that substantially exceeds our net tangible book value per share after giving effect to this offering. If you purchase common stock in this offering, you will incur an immediate and substantial dilution in net tangible book value of $      per share, based on the public offering price of $      per share. For a further description of the dilution that you will experience immediately after this offering, see “Dilution.” In addition, in the past, we have issued options and warrants to acquire common stock at prices significantly below the offering price and have granted restricted stock units. To the extent these outstanding options and warrants are ultimately exercised or these restricted stock units vest, you will incur additional dilution.
Our management will have broad discretion over the use of the net proceeds from this offering, and you may not agree with how we use the proceeds and the proceeds may not be invested successfully.
Our management will have broad discretion as to the use of the net proceeds from this offering and could use them for purposes other than those contemplated at the time of this offering. Accordingly, you are relying on the judgment of our management with regard to the use of these net proceeds, and you will not have the opportunity, as part of your investment decision, to assess whether the proceeds will be used appropriately. It is possible that the proceeds will be invested in a way that does not yield a favorable, or any, return for us.
Because we do not anticipate paying any cash dividends on our capital stock in the foreseeable future, capital appreciation, if any, will be your sole source of gain.
We have never declared or paid cash dividends on our capital stock. In addition, the terms of our indebtedness with Hercules Capital, Inc. prohibit us from paying dividends. We anticipate that we will retain our earnings, if any, for future growth and therefore do not anticipate paying cash dividends in the future. As a result, only appreciation of the price of our common stock will provide a return to stockholders.
Sales of a significant number of shares of our common stock in the public markets, or the perception that such sales could occur, could depress the market price of our common stock.
Sales of a substantial number of shares of our common stock in the public markets could depress the market price of our common stock and impair our ability to raise capital through the sale of additional equity securities. We, our executive officers and directors and certain of their affiliates have agreed not to sell, dispose of or hedge any common stock or securities convertible into or exchangeable for shares of common stock during the period from the date of this prospectus supplement continuing through and including the date 90 days after the date of this prospectus supplement, subject to certain exceptions. The underwriters may, in their discretion, release the restrictions on any such shares at any time without notice. We cannot predict the effect that future sales of our common stock would have on the market price of our common stock. With the exception of the shares held by our executive officers and directors and certain of their affiliates that are subject to the restrictions described above, substantially all of the outstanding shares of our common stock are eligible to be sold into the public markets without restriction.
 
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Special note regarding forward-looking statements
This prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein include forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Exchange Act that relate to future events or our future financial performance and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to differ materially from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Words such as, but not limited to, “believe,” “expect,” “estimate,” “intend,” “plan,” “potential,” “predict,” “project,” “targets,” “likely,” “will,” “would,” “could,” “should,” “continue,” and similar expressions or phrases, or the negative of those expressions or phrases, are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Although we believe that we have a reasonable basis for each forward-looking statement contained in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein, we caution you that these statements are based on our projections of the future that are subject to known and unknown risks and uncertainties and other factors that may cause our actual results, level of activity, performance or achievements expressed or implied by these forward-looking statements, to differ. The sections in our periodic reports, including our Annual Report on Form 10-K for the fiscal year ended December 31, 2019, entitled “Business,” “Risk Factors,” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” as well as other sections in this prospectus supplement, the accompanying prospectus and the documents or reports incorporated by reference herein and therein discuss some of the factors that could contribute to these differences. These forward-looking statements include, among other things, statements about:

the implementation of our business model and strategic plans for our business, products and services;

the potential size of the markets and fields addressable by our Simoa technology platforms;

the commercialization and adoption of our existing products and services and the success of our new product offerings;

our ability to develop additional assays, including multiplexed assays;

the accuracy of our estimates regarding expenses, future revenues, capital requirements and our needs for additional financing;

the ability of our Simoa technology’s sensitivity to improve existing diagnostics and to enable the development of new diagnostic tests and tools;

the potential of our Simoa technology in the field of companion diagnostics and its adoption by healthcare professionals;

the impact of our Simoa technology on proteomic research;

the usefulness of the data generated by our Simoa technology in the life science research, diagnostic and precision health screening fields;

the impact of COVID-19 on our business; and

our financial performance.
We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. We have included important cautionary statements in this prospectus supplement or in the documents incorporated by reference in this prospectus supplement, particularly in the “Risk factors” section, that we believe could cause actual results or events to differ materially from the forward-looking statements that we make. For a summary of such factors, please refer to the section entitled “Risk factors” in this prospectus supplement, our most recent Annual Report on Form 10-K, as revised or supplemented by our subsequent quarterly reports on Form 10-Q or current reports on Form
 
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8-K, as well as any amendments thereto, as filed with the SEC and which are incorporated herein by reference. The information contained in this document is believed to be current as of the date of this document. We do not intend to update any of the forward-looking statements after the date of this document to conform these statements to actual results or to changes in our expectations, except as required by law.
In light of these assumptions, risks and uncertainties, the results and events discussed in the forward-looking statements contained in this prospectus or in any document incorporated herein by reference might not occur. Investors are cautioned not to place undue reliance on the forward-looking statements, which speak only as of the date of this prospectus or the date of the document incorporated by reference in this prospectus. We are not under any obligation, and we expressly disclaim any obligation, to update or alter any forward-looking statements, whether as a result of new information, future events or otherwise. All subsequent forward-looking statements attributable to us or to any person acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this section.
 
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Use of proceeds
We estimate that the net proceeds we will receive from this offering will be approximately $      million after deducting underwriting discounts and commissions and estimated offering expenses payable by us. If the underwriters exercise their option to purchase additional shares in full, we estimate that our net proceeds will be approximately $      million, after deducting underwriting discounts and commissions and estimated offering expenses payable by us.
We currently intend to use the net proceeds from this offering to (1) to expand our life sciences commercial operations to grow and support the installed base of our products among life sciences customers in the United States and internationally; (2) to improve and update our Simoa technology and instruments and to develop additional assays; (3) to potentially pursue regulatory approvals or clearances to develop instruments, assay kits and consumables in areas outside of life science research and, subject to receipt of such necessary regulatory approvals or clearances, to develop such instruments, assay kits and consumables; (4) to potentially pursue acquisitions or other business development opportunities; and (5) for working capital and other general corporate purposes, including, but not limited to, capital expenditures, investments, and collaborations.
Although we currently anticipate that we will use the net proceeds from this offering as described above, there may be circumstances where a reallocation of funds is necessary. Due to the uncertainties inherent in the product development process, it is difficult to estimate with certainty the exact amounts of the net proceeds from this offering that may be used for the above purposes. The amounts and timing of our actual expenditures will depend upon numerous factors, including our sales and marketing and commercialization efforts, demand for our technology, our operating costs and the other factors described under “Risk factors” in this prospectus supplement and the documents incorporated by reference herein. Accordingly, our management will have flexibility in applying the net proceeds from this offering. An investor will not have the opportunity to evaluate the economic, financial or other information on which we base our decisions on how to use the proceeds.
Pending their use as described above, we plan to invest the net proceeds in short-term, interest-bearing obligations, investment-grade instruments, certificates of deposit or guaranteed obligations of the U.S. government.
 
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Dividend policy
We have never declared or paid cash dividends on our capital stock. We currently intend to retain all available funds and future earnings, if any, for use in the operation of our business and do not anticipate paying any cash dividends on our common stock in the foreseeable future. In addition, the terms of our indebtedness with Hercules Capital, Inc. prohibit us from paying dividends. Any future determination to declare and pay dividends will be made at the discretion of our Board of Directors and will depend on various factors, including applicable laws, our results of operations, our financial condition, our capital requirements, general business conditions, our future prospects and other factors that our Board of Directors may deem relevant.
 
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Dilution
If you invest in our common stock, your interest will be diluted to the extent of the difference between the price per share of our common stock you pay in this offering and the as adjusted net tangible book value per share of our common stock immediately after this offering.
As of September 30, 2020, our historical net tangible book value was $186.1 million, or $5.89 per share of common stock. Historical net tangible book value per share represents the amount of our total tangible assets less total liabilities, divided by 31,583,509, the number of shares of common stock outstanding as of September 30, 2020.
After giving effect to the sale of an aggregate of           shares of our common stock at the public offering price of $      per share, and after deducting commissions and estimated offering expenses payable by us, our as adjusted net tangible book value as of September 30, 2020 would have been $      million, or $      per share of common stock. This amount represents an immediate increase in net tangible book value of $      per share to our existing stockholders and an immediate dilution in net tangible book value of approximately $      per share to new investors in this offering.
The following table illustrates this calculation on a per share basis.
Public offering price per share
$      
Historical net tangible book value per share as of September 30, 2020
$ 5.89
Increase in net tangible book value per share attributable to new investors
Net tangible book value per share after the offering
Dilution per share to new investors
$
If the underwriters exercise their option to purchase           additional shares in full at the public offering price of $      per share, the net tangible book value per share after giving effect to the offering would be $      per share. This represents an immediate increase in as adjusted net tangible book value of $      per share to existing stockholders and an immediate dilution in net tangible book value of $      per share to new investors purchasing shares of our common stock in this offering.
The table above does not include:

2,633,486 shares of our common stock issuable upon the exercise of stock options outstanding as of September 30, 2020, at a weighted average exercise price of $16.98 per share, of which 1,514,433 shares were vested as of such date;

453,212 shares of our common stock issuable upon the vesting of restricted stock units outstanding as of September 30, 2020;

10,000 shares of our common stock issuable upon the exercise of warrants outstanding as of September 30, 2020, at an exercise price of $21.00 per share;

809,802 shares of common stock reserved for future issuance under the 2017 Employee, Director and Consultant Equity Incentive Plan as of September 30, 2020; and

848,269 shares of common stock reserved for future issuance under the 2017 Employee Stock Purchase Plan as of September 30, 2020.
To the extent that outstanding options or warrants are exercised or restricted stock units are vested, you will experience further dilution. In addition, we may choose to raise additional capital due to market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. To the extent that additional capital is raised through the sale of equity or convertible debt securities, the issuance of these securities may result in further dilution to our stockholders.
 
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Material U.S. federal income and estate tax consequences to non-U.S. holders
The following is a summary of the material U.S. federal income tax consequences of the ownership and disposition of our common stock to Non-U.S. Holders (defined below), but does not purport to be a complete analysis of all the potential tax considerations relating thereto. This summary is based upon the provisions of the Internal Revenue Code of 1986, as amended, or the Code, Treasury regulations promulgated thereunder, administrative rulings and judicial decisions, all as of the date of this prospectus. These authorities may be changed or subject to differing interpretations, possibly with retroactive effect, so as to result in U.S. federal income tax consequences different from those set forth below. We have not sought and will not seek any ruling from the Internal Revenue Service (the “IRS”), with respect to the statements made and the conclusions reached in the following summary, and there can be no assurance that the IRS or a court will agree with such statements and conclusions.
This summary also does not address the tax considerations arising under the laws of any U.S. state or local or any non-U.S. jurisdiction, the 3.8% Medicare tax on net investment income or any alternative minimum tax consequences. In addition, this discussion does not address tax considerations applicable to a Non-U.S. Holder’s particular circumstances or to a Non-U.S. Holder that may be subject to special tax rules, including, without limitation:

banks, insurance companies or other financial institutions;

tax-exempt or government organizations;

brokers of or dealers in securities or currencies;

traders in securities that elect to use a mark-to-market method of accounting for their securities holdings;

persons that own, or are deemed to own, more than five percent of our capital stock;

certain U.S. expatriates, citizens or former long-term residents of the United States;

persons who hold our common stock as a position in a hedging transaction, “straddle;” “conversion transaction,” synthetic security, other integrated investment, or other risk reduction transaction;

persons who do not hold our common stock as a capital asset within the meaning of Section 1221 of the Code (generally, for investment purposes);

persons deemed to sell our common stock under the constructive sale provisions of the Code; real estate investment trusts, regulated investment companies or mutual funds;

pension plans;

partnerships, or other entities or arrangements treated as partnerships for U.S. federal income tax purposes, or investors in any such entities;

persons for whom our stock constitutes “qualified small business stock” within the meaning of Section 1202 of the Code;

integral parts or controlled entities of foreign sovereigns;

tax-qualified retirement plans;

controlled foreign corporations;

passive foreign investment companies and corporations that accumulate earnings to avoid U.S. federal income tax; or

persons that acquire our common stock as compensation for services.
In addition, if a partnership, including any entity or arrangement classified as a partnership for U.S. federal income tax purposes, holds our common stock, the tax treatment of a partner generally will depend on the status of the partner, the activities of the partnership, and certain determinations made at the partner level. Accordingly, partnerships that hold our common stock, and partners in such
 
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partnerships, should consult their tax advisors regarding the U.S. federal income tax consequences to them of the purchase, ownership, and disposition of our common stock.
You are urged to consult your tax advisor with respect to the application of the U.S. federal income tax laws to your particular situation, as well as any tax consequences of the purchase, ownership and disposition of our common stock arising under the U.S. federal estate or gift tax rules or under the laws of any U.S. state or local or any non-U.S. or other taxing jurisdiction or under any applicable tax treaty.
Definition of a non-U.S. holder
For purposes of this summary, a “Non-U.S. Holder” is any beneficial owner of our common stock that is, for U.S. federal income tax purposes, neither an entity disregarded from its owner, a partnership, nor a “U.S. person.” A U.S. person is any person that, for U.S. federal income tax purposes, is or is treated as any of the following:

an individual who is a citizen or resident of the United States;

a corporation (or other entity classified for U.S. federal income tax purposes as a corporation) created or organized under the laws of the United States, any state thereof, or the District of Columbia;

an estate, the income of which is subject to U.S. federal income tax regardless of its source; or

a trust that (1) is subject to the primary supervision of a U.S. court and the control of one or more U.S. persons (within the meaning of Section 7701(a)(30) of the Code), or (2) has a valid election in effect to be treated as a U.S. person for U.S. federal income tax purposes.
Distributions
As discussed under “Dividend policy,” above, we do not anticipate paying any dividends on shares of our capital stock in the foreseeable future. If we make distributions on a share of our common stock, those payments will constitute dividends for U.S. income tax purposes to the extent paid from our current or accumulated earnings and profits, as determined under U.S. federal income tax principles. To the extent those distributions exceed both our current and our accumulated earnings and profits, they will constitute a return of capital and will first reduce a Non-U.S. Holder’s basis in such share of our common stock, but not below zero. Any excess will be treated as capital gain and will be treated as described below under “Gain on sale or other disposition of common stock.” Any such distributions would be subject to the discussions below regarding back-up withholding and FATCA.
Subject to the discussion below on effectively connected income, any dividend paid to a Non-U.S. Holder generally will be subject to U.S. withholding tax either at a rate of 30% of the gross amount of the dividend or such lower rate as may be specified by an applicable income tax treaty. In order to receive a reduced treaty rate, a Non-U.S. Holder must provide us or our agent with an IRS Form W-8BEN-E (generally including a U.S. taxpayer identification number), IRS Form W-8-BEN-E or another appropriate version of IRS Form W-8 (or a successor form), which must be updated periodically, and which, in each case, must certify qualification for the reduced rate. Non-U.S. Holders should consult their tax advisors regarding their entitlement to benefits under any applicable income tax treaty.
Dividends paid to a Non-U.S. Holder that are effectively connected with the Non-U.S. Holder’s conduct of a trade or business within the United States (and, if there is an applicable income tax treaty, are attributable to a permanent establishment maintained by the Non-U.S. Holder in the United States) generally are exempt from the withholding tax described above. In order to obtain this exemption, the Non-U.S. Holder must provide the applicable withholding agent with an IRS Form W-8ECI or successor form or other applicable IRS Form W-8 certifying that the dividends are effectively connected with the Non-U.S. Holder’s conduct of a trade or business within the United States. Such effectively connected dividends, although not subject to withholding tax, are taxed at the same graduated rates applicable to U.S. persons, net of certain deductions and credits, subject to an applicable income tax treaty providing otherwise. In addition, if you are a Non-U.S. Holder that is a corporation, dividends you receive that are
 
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effectively connected with your conduct of a U.S. trade or business (and, if an income tax treaty applies, are attributable to a permanent establishment maintained by you in the United States) may also be subject to a branch profits tax at a rate of 30% (or such lower rate as may be specified by an applicable income tax treaty) on such effectively connected dividends, as adjusted for certain items.
If you are eligible for a reduced rate of withholding tax pursuant to a tax treaty, you may be able to obtain a refund of any excess amounts currently withheld if you timely file an appropriate claim for refund with the IRS.
Gain on sale or other disposition of common stock
Subject to the discussion below regarding backup withholding and FATCA, a Non-U.S. Holder generally will not be required to pay U.S. federal income tax on any gain realized upon the sale or other disposition of our common stock unless:

the gain is effectively connected with the Non-U.S. Holder’s conduct of a trade or business within the United States (and, if an income tax treaty applies, the gain is attributable to a permanent establishment maintained by the Non-U.S. Holder in the United States), in which case the Non-U.S. Holder will be required to pay tax on the net gain derived from the sale under regular graduated U.S. federal income tax rates, and for a Non-U.S. Holder that is a corporation, such Non-U.S. Holder may be subject to the branch profits tax at a 30% rate (or such lower rate as may be specified by an applicable income tax treaty) on such effectively connected dividends, as adjusted for certain items;

the Non-U.S. Holder is an individual who is present in the United States for a period or periods aggregating 183 days or more during the calendar year in which the sale or disposition occurs and certain other conditions are met, in which case the Non-U.S. Holder will be required to pay a flat 30% tax on the gain derived from the sale, which tax may be offset by U.S. source capital losses (even though the Non-U.S. Holder is not considered a resident of the United States) (subject to applicable income tax or other treaties); or

our common stock constitutes a U.S. real property interest by reason of our status as a U.S. real property holding corporation (a “USRPHC”) for U.S. federal income tax purposes at any time within the shorter of the five-year period preceding the disposition or the Non-U.S. Holder’s holding period for our common stock. We believe we are not currently and do not anticipate becoming a USRPHC. However, because the determination of whether we are a USRPHC depends on the fair market value of our U.S. real property interests relative to the fair market value of our other business assets, there can be no assurance that we will not become a USRPHC in the future. Even if we become a USRPHC, however, gain arising from the sale or other taxable disposition by a Non-U.S. Holder of our common stock will not be subject to U.S. federal income tax as long as our common stock is regularly traded on an established securities market and such Non-U.S. Holder does not, actually or constructively, hold more than five percent of our common stock at any time during the applicable period that is specified in the Code. If the foregoing exception does not apply, then if we are or were to become a USRPHC a purchaser may be required to withhold 15% of the proceeds payable to a Non-U.S. Holder from a sale of our common stock and such Non-U.S. Holder generally will be taxed on its net gain derived from the disposition at the graduated U.S. federal income tax rates applicable to United States persons (as defined in the Code).
Backup withholding and information reporting
Generally, we must file information returns annually to the IRS in connection with any dividends on our common stock paid to a Non-U.S. Holder, regardless of whether any tax was withheld. A similar report will be sent to the Non-U.S. Holder. Pursuant to applicable income tax treaties or other agreements, the IRS may make these reports available to tax authorities in the Non-U.S. Holder’s country of residence.
Payments of dividends or of proceeds on the disposition of stock made to a Non-U.S. Holder may be subject to additional information reporting and backup withholding at a current rate of 24% unless
 
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such Non-U.S. Holder establishes an exemption, for example by properly certifying its non-U.S. status on an IRS Form W-8BEN, IRS Form W-8BEN-E, IRS Form W-8ECI, or another appropriate version of IRS Form W-8 (or a successor form). Notwithstanding the foregoing, backup withholding and information reporting may apply if either we or our paying agent has actual knowledge, or reason to know, that a holder is a U.S. person.
Backup withholding is not an additional tax; rather, the U.S. income tax liability of persons subject to backup withholding will be reduced by the amount of tax withheld. If withholding results in an overpayment of taxes, a refund or credit may generally be obtained from the IRS, provided that the required information is furnished to the IRS in a timely manner.
Foreign Account Tax Compliance Act
The Foreign Account Tax Compliance Act, or FATCA, imposes withholding tax on certain types of payments made to foreign financial institutions and certain other non-U.S. entities. The law imposes a 30% withholding tax on dividends we pay with respect to our common stock to a “foreign financial institution” or to certain “non-financial foreign entities” ​(each as defined in the Code), unless (i) the foreign financial institution undertakes certain diligence and reporting obligations, (ii) the non-financial foreign entity either certifies it does not have any “substantial United States owners” ​(as defined in the Code) or furnishes identifying information regarding each substantial United States owner, or (iii) the foreign financial institution or non-financial foreign entity otherwise qualifies for an exemption from these rules. If the payee is a foreign financial institution and is subject to the diligence and reporting requirements in (i) above, it must enter into an agreement with the U.S. Treasury requiring, among other things, that it undertake to identify accounts held by “specified United States persons” or “United States-owned foreign entities” ​(each as defined in the Code), annually report certain information about such accounts, and withhold 30% on payments to account holders whose actions prevent it from complying with these reporting and other requirements. If the country in which a payee is resident has entered into an “intergovernmental agreement” with the United States regarding FATCA, that agreement may permit the payee to report to that country rather than to the U.S. Department of the Treasury. Prospective investors should consult their own tax advisors regarding the possible impact of these rules on their investment in our common stock, and the possible impact of these rules on the entities through which they hold our common stock, including, without limitation, the process and deadlines for meeting the applicable requirements to prevent the imposition of this 30% withholding tax under FATCA.
Under U.S. Treasury regulations proposed on December 18, 2018, on which the IRS has stated taxpayers may rely until final regulations are issued, withholding under FATCA that would otherwise have potentially applied to gross proceeds from a sale or other disposition of our common stock made after December 31, 2018, has been eliminated.
Federal estate tax
Common stock we have issued that is owned (or treated as owned) by an individual who is not a citizen or a resident of the United States (as defined for U.S. federal estate tax purposes) at the time of death will be included in the individual’s gross estate for U.S. federal estate tax purposes unless an applicable estate or other tax treaty provides otherwise, and therefore may be subject to U.S. federal estate tax.
The preceding discussion of U.S. federal tax considerations is for general information only. It is not tax advice. Each prospective investor should consult its tax advisor regarding the particular U.S. federal, state and local and non-U.S. tax consequences of purchasing, holding and disposing of our common stock, including the consequences of any proposed change in applicable laws.
 
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Underwriting
We and the underwriters named below have entered into an underwriting agreement with respect to the shares being offered. Subject to certain conditions, each underwriter has severally agreed to purchase the number of shares indicated in the following table. Goldman Sachs & Co. LLC, SVB Leerink LLC and Cowen and Company, LLC are the representatives of the underwriters.
Underwriters
Number of Shares
Goldman Sachs & Co. LLC
      
SVB Leerink LLC
Cowen and Company, LLC
Canaccord Genuity LLC
Total
The underwriters are committed to take and pay for all of the shares being offered, if any are taken, other than the shares covered by the option described below unless and until this option is exercised.
The underwriters have an option to buy up to an additional             shares of our common stock from us. They may exercise that option for 30 days. If any shares are purchased pursuant to this option, the underwriters will severally purchase shares in approximately the same proportion as set forth in the table above.
The following tables show the per share and total underwriting discounts and commissions to be paid to the underwriters by us. Such amounts are shown assuming both no exercise and full exercise of the underwriters’ option to purchase             additional shares of our common stock from us.
Paid by the Company
No Exercise
Full Exercise
Per Share
$      $     
Total
$ $
Shares sold by the underwriters to the public will initially be offered at the initial public offering price set forth on the cover of this prospectus. Any shares sold by the underwriters to securities dealers may be sold at a discount of up to $      per share from the initial public offering price. After the initial offering of the shares, the representatives may change the offering price and the other selling terms. The offering of the shares by the underwriters is subject to receipt and acceptance and subject to the underwriters’ right to reject any order in whole or in part.
We and our officers, directors, and certain of our other existing security holders, have agreed with the underwriters, subject to certain exceptions, not to sell or transfer any common stock or securities convertible into or exchangeable or exercisable for common stock, for 90 days after the date of the final prospectus supplement of this offering without first obtaining the written consent of Goldman Sachs & Co. LLC, SVB Leerink LLC and Cowen and Company, LLC on behalf of the underwriters. Specifically, we and these other persons have agreed, with certain limited exceptions, not to directly or indirectly:

offer, pledge, sell or contract to sell any common stock;

sell any option or contract to purchase any common stock;

purchase any option or contract to sell any common stock;

grant any option, right or warrant for the sale of any common stock;

otherwise dispose of or transfer any common stock;

request or demand that we file a registration statement related to the common stock; or
 
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enter into any swap or other agreement or any transaction that transfers, in whole or in part, the economic consequence of ownership of any common stock, whether any such swap, agreement or transaction is to be settled by delivery of shares or other securities, in cash or otherwise.
The lock-up provisions apply to common stock and to securities convertible into or exchangeable or exercisable for common stock. They also apply to common stock owned now or acquired later by the person executing the lock-up agreement or for which the person executing the lock-up agreement later acquires the power of disposition.
However, each such locked-up party has agreed that, subject to certain conditions, the foregoing restrictions shall not apply to certain transactions, including:
(i)   transfers of shares of common stock as a bona fide gift or gifts or to a trust the beneficiaries of which are exclusively such locked-up party or members of their immediate family, or by will or intestate succession upon the death of such locked-up party;
(ii)   if the locked-up party is a corporation, partnership, limited liability company or other business entity, distributions of shares of common stock to members or stockholders of such locked-up party;
(iii)   if the locked-up party is a corporation, partnership, limited liability company or other business entity, any transfer made by such locked-up party to another corporation, partnership, limited liability company or other business entity so long as the transferee controls, is controlled by or is under common control with such locked-up party and such transfer is not for value;
(iv)   transactions relating to common stock or other securities convertible into or exercisable or exchangeable for common stock acquired by such locked-up party in this offering or in open market transactions after completion of this offering;
(v)   the entry into any trading plan providing for the sale of common stock by such locked-up party, which trading plan (a “10b5-1 Plan”) meets the requirements of Rule 10b5-1(c) under the Exchange Act, provided, however, that such plan does not provide for, or permit, the sale of any common stock during the lock-up period and no filing under Section 16(a) of the Exchange Act or other public announcement is voluntarily made or required regarding such plan during the lock-up period;
(vi)   any transfers or dispositions made by or on behalf of the locked-up party solely to satisfy tax withholding obligations pursuant to our equity incentive plans or arrangements disclosed in this prospectus, provided that no filing under Section 16(a) of the Exchange Act or other public announcement is voluntarily made regarding such transfers during the lock-up, and provided, further, that any filing required under Section 16(a) of the Exchange Act shall clearly indicate in the codes and footnotes thereto that any such disposition of shares was made solely to satisfy the locked-up party’s tax withholding obligations;
(vii)   any transfers made by such locked-up party by operation of law, such as pursuant to a qualified domestic order or in connection with a divorce settlement;
(viii)   any transfers to us pursuant to agreements under which we have the option to repurchase shares or shares are forfeited upon termination of service of such locked-up party;
(ix)   dispositions solely in connection with the “cashless” exercise of stock options or warrants to acquire shares of common stock described in this prospectus or issued pursuant to an equity plan or arrangement described in this prospectus for the purpose of exercising such stock options or warrants, in any event, solely if such stock options or warrants would otherwise expire, provided that any shares of common stock received upon such exercise shall be subject to all of the lock-up restrictions), provided, further, that any filing required under Section 16(a) of the Exchange Act shall clearly indicate in the codes and footnotes thereto that any disposition of shares in connection with a “cashless” exercise was made solely to us;
 
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(x)   shares to be sold in this offering by the locked-up parties, if any, pursuant to the underwriting agreement;
(xi)   distributions by funds affiliated with one of our institutional shareholders to their limited partners of up to 850,000 shares of common stock, starting 30 days after the date of this prospectus supplement; and
(xii)   transfers of shares of common stock by certain locked-up parties pursuant to existing 10b5-1 Plans, which 10b5-1 Plan shall not be amended during the lock-up period but may be terminated during the lock-up period, provided that to the extent a public announcement or filing under the Exchange Act, if any, is required of or voluntarily made by or on behalf of the locked-up party or us regarding sales made under the locked-up party’s 10b5-1 Plan, such announcement or filing shall include a statement to the effect that such sales of common stock are being made pursuant to the locked-up party’s 10b5-1 Plan established prior to the date hereof,
provided, that, in the case of any transfer or distribution pursuant to clause (i), (ii), (iii) or (vii) above, each donee, distributee or transferee, as applicable, shall execute and deliver to the representatives a lock-up agreement; and provided, further, that in the case of any transfer or distribution pursuant to clause (i), (ii), (iii) or (iv) above, no filing by any party (donor, donee, transferor or transferee) under the Exchange Act, or other public announcement reporting a reduction in beneficial ownership shall be required or shall be made voluntarily in connection with such transfer or distribution (other than a filing on a Form 5, Schedule 13G (or Schedule 13G/A) or Schedule 13F made after the expiration of the lock-up period referred to above).
Our common stock is listed on the Nasdaq Global Market under the symbol “QTRX.”
In connection with the offering, the underwriters may purchase and sell shares of common stock in the open market. These transactions may include short sales, stabilizing transactions and purchases to cover positions created by short sales. Short sales involve the sale by the underwriters of a greater number of shares than they are required to purchase in the offering, and a short position represents the amount of such sales that have not been covered by subsequent purchases. A “covered short position” is a short position that is not greater than the amount of additional shares for which the underwriters’ option described above may be exercised. The underwriters may cover any covered short position by either exercising their option to purchase additional shares or purchasing shares in the open market. In determining the source of shares to cover the covered short position, the underwriters will consider, among other things, the price of shares available for purchase in the open market as compared to the price at which they may purchase additional shares pursuant to the option described above. “Naked” short sales are any short sales that create a short position greater than the amount of additional shares for which the option described above may be exercised. The underwriters must cover any such naked short position by purchasing shares in the open market. A naked short position is more likely to be created if the underwriters are concerned that there may be downward pressure on the price of the common stock in the open market after pricing that could adversely affect investors who purchase in the offering. Stabilizing transactions consist of various bids for or purchases of common stock made by the underwriters in the open market prior to the completion of the offering.
The underwriters may also impose a penalty bid. This occurs when a particular underwriter repays to the underwriters a portion of the underwriting discount received by it because the representatives have repurchased shares sold by or for the account of such underwriter in stabilizing or short covering transactions.
Purchases to cover a short position and stabilizing transactions, as well as other purchases by the underwriters for their own accounts, may have the effect of preventing or retarding a decline in the market price of our stock, and together with the imposition of the penalty bid, may stabilize, maintain or otherwise affect the market price of the common stock. As a result, the price of the common stock may be higher than the price that otherwise might exist in the open market. The underwriters are not required to engage in these activities and may end any of these activities at any time. These transactions may be effected on the Nasdaq Global Market, in the over-the-counter market or otherwise.
 
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European Economic Area
In relation to each EEA Member State (each a “Relevant Member State”), no Offer Shares have been offered or will be offered pursuant to the Offering to the public in that Relevant Member State prior to the publication of a prospectus in relation to the Offer Shares which has been approved by the competent authority in that Relevant Member State or, where appropriate, approved in another Relevant Member State and notified to the competent authority in that Relevant Member State, all in accordance with the Prospectus Regulation, except that the Offer Shares may be offered to the public in that Relevant Member State at any time:
(i)
to any legal entity which is a qualified investor as defined under Article 2 of the Prospectus Regulation;
(ii)
to fewer than 150 natural or legal persons (other than qualified investors as defined under Article 2 of the Prospectus Regulation) subject to obtaining the prior consent of the Joint Global Coordinators for any such offer; or
(iii)
in any other circumstances falling within Article 1(4) of the Prospectus Regulation,
provided that no such offer of the Offer Shares shall require the Company and/or Selling Shareholders or any Bank to publish a prospectus pursuant to Article 3 of the Prospectus Regulation or supplement a prospectus pursuant to Article 23 of the Prospectus Regulation.
For the purposes of this provision, the expression an ‘offer to the public’ in relation to the Offer Shares in any Relevant Member State means the communication in any form and by any means of sufficient information on the terms of the offer and any Offer Shares to be offered so as to enable an investor to decide to purchase any Offer Shares, and the expression “Prospectus Regulation” means Regulation (EU) 2017/1129.
Each person in a Relevant Member State who receives any communication in respect of, or who acquires any Offer Shares under, the Offering contemplated hereby will be deemed to have represented, warranted and agreed to and with each of the Underwriters and their affiliates and the Company that:
(i)
it is a qualified investor within the meaning of the Prospectus Regulation; and
(ii)
in the case of any Offer Shares acquired by it as a financial intermediary, as that term is used in Article 5 of the Prospectus Regulation, (i) the Offer Shares acquired by it in the Offering have not been acquired on a non-discretionary basis on behalf of, nor have they been acquired with a view to their offer or resale to, persons in any Relevant Member State other than qualified investors, as that term is defined in the Prospectus Regulation, or have been acquired in other circumstances falling within the points (a) to (d) of Article 1(4) of the Prospectus Regulation and the prior consent of the Joint Global Coordinators has been given to the offer or resale; or (ii) where the Offer Shares have been acquired by it on behalf of persons in any Relevant Member State other than qualified investors, the offer of those Offer Shares to it is not treated under the Prospectus Regulation as having been made to such persons.
The Company, the Underwriters and their affiliates, and others will rely upon the truth and accuracy of the foregoing representation, acknowledgement and agreement. Notwithstanding the above, a person who is not a qualified investor and who has notified the Joint Global Coordinators of such fact in writing may, with the prior consent of the Joint Global Coordinators, be permitted to acquire Offer Shares in the Offering.
United Kingdom
This Prospectus and any other material in relation to the Offer Shares described herein is only being distributed to, and is only directed at, and any investment or investment activity to which this Prospectus relates is available only to, and will be engaged in only with persons who are (i) persons having professional experience in matters relating to investments who fall within the definition of investment professionals in Article 19(5) of the FPO; or (ii) high net worth entities falling within Article 49(2)(a) to (d) of the FPO; (iii) outside the UK; or (iv) persons to whom an invitation or inducement
 
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to engage in investment activity (within the meaning of Section 21 of the FSMA) in connection with the issue or sale of any Offer Shares may otherwise lawfully be communicated or caused to be communicated, (all such persons together being referred to as “Relevant Persons”). The Offer Shares are only available in the UK to, and any invitation, offer or agreement to purchase or otherwise acquire the Offer Shares will be engaged in only with, the Relevant Persons. This Prospectus and its contents are confidential and should not be distributed, published or reproduced (in whole or in part) or disclosed by recipients to any other person in the UK. Any person in the UK that is not a Relevant Person should not act or rely on this Prospectus or any of its contents.
No Offer Shares have been offered or will be offered pursuant to the Offering to the public in the United Kingdom prior to the publication of a prospectus in relation to the Offer Shares which has been approved by the Financial Conduct Authority, except that the Offer Shares may be offered to the public in the United Kingdom at any time:
(i)
to any legal entity which is a qualified investor as defined under Article 2 of the UK Prospectus Regulation;
(ii)
to fewer than 150 natural or legal persons (other than qualified investors as defined under Article 2 of the UK Prospectus Regulation), subject to obtaining the prior consent of the Global Coordinators for any such offer; or
(iii)
in any other circumstances falling within Section 86 of the FSMA.
provided that no such offer of the Offer Shares shall require the Company and/or any Underwriters or any of their affiliates to publish a prospectus pursuant to Section 85 of the FSMA or supplement a prospectus pursuant to Article 23 of the UK Prospectus Regulation. For the purposes of this provision, the expression an “offer to the public” in relation to the Offer Shares in the United Kingdom means the communication in any form and by any means of sufficient information on the terms of the offer and any Offer Shares to be offered so as to enable an investor to decide to purchase or subscribe for any Offer Shares and the expression “UK Prospectus Regulation” means Regulation (EU) 2017/1129 as it forms part of domestic law by virtue of the European Union (Withdrawal) Act 2018.
Each person in the UK who acquires any Offer Shares in the Offer or to whom any offer is made will be deemed to have represented, acknowledged and agreed to and with the Company, the Underwriters and their affiliates that it meets the criteria outlined in this section.
Canada
The securities may be sold in Canada only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument 31-103 Registration Requirements, Exemptions, and Ongoing Registrant Obligations. Any resale of the securities must be made in accordance with an exemption form, or in a transaction not subject to, the prospectus requirements of applicable securities laws.
Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this offering memorandum (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory of these rights or consult with a legal advisor.
Pursuant to section 3A.3 of National Instrument 33-105 Underwriting Conflicts (NI 33-105), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this offering.
Hong Kong
The shares may not be offered or sold in Hong Kong by means of any document other than (i) in circumstances which do not constitute an offer to the public within the meaning of the Companies
 
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(Winding Up and Miscellaneous Provisions) Ordinance (Cap. 32 of the Laws of Hong Kong) (“Companies (Winding Up and Miscellaneous Provisions) Ordinance”) or which do not constitute an invitation to the public within the meaning of the Securities and Futures Ordinance (Cap. 571 of the Laws of Hong Kong) (“Securities and Futures Ordinance”), or (ii) to “professional investors” as defined in the Securities and Futures Ordinance and any rules made thereunder, or (iii) in other circumstances which do not result in the document being a “prospectus” as defined in the Companies (Winding Up and Miscellaneous Provisions) Ordinance, and no advertisement, invitation or document relating to the shares may be issued or may be in the possession of any person for the purpose of issue (in each case whether in Hong Kong or elsewhere), which is directed at, or the contents of which are likely to be accessed or read by, the public in Hong Kong (except if permitted to do so under the securities laws of Hong Kong) other than with respect to shares which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” in Hong Kong as defined in the Securities and Futures Ordinance and any rules made thereunder.
Singapore
This prospectus has not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the shares may not be circulated or distributed, nor may the shares be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor (as defined under Section 4A of the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”)) under Section 274 of the SFA, (ii) to a relevant person (as defined in Section 275(2) of the SFA) pursuant to Section 275(1) of the SFA, or any person pursuant to Section 275(1A) of the SFA, and in accordance with the conditions specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA, in each case subject to conditions set forth in the SFA.
Where the shares are subscribed or purchased under Section 275 of the SFA by a relevant person which is a corporation (which is not an accredited investor (as defined in Section 4A of the SFA)) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor, the securities (as defined in Section 239(1) of the SFA) of that corporation shall not be transferable for 6 months after that corporation has acquired the shares under Section 275 of the SFA except: (1) to an institutional investor under Section 274 of the SFA or to a relevant person (as defined in Section 275(2) of the SFA), (2) where such transfer arises from an offer in that corporation’s securities pursuant to Section 275(1A) of the SFA, (3) where no consideration is or will be given for the transfer, (4) where the transfer is by operation of law, (5) as specified in Section 276(7) of the SFA, or (6) as specified in Regulation 32 of the Securities and Futures (Offers of Investments) (Shares and Debentures) Regulations 2005 of Singapore (“Regulation 32”)
Where the shares are subscribed or purchased under Section 275 of the SFA by a relevant person which is a trust (where the trustee is not an accredited investor (as defined in Section 4A of the SFA)) whose sole purpose is to hold investments and each beneficiary of the trust is an accredited investor, the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferable for 6 months after that trust has acquired the shares under Section 275 of the SFA except: (1) to an institutional investor under Section 274 of the SFA or to a relevant person (as defined in Section 275(2) of the SFA), (2) where such transfer arises from an offer that is made on terms that such rights or interest are acquired at a consideration of not less than S$200,000 (or its equivalent in a foreign currency) for each transaction (whether such amount is to be paid for in cash or by exchange of securities or other assets), (3) where no consideration is or will be given for the transfer, (4) where the transfer is by operation of law, (5) as specified in Section 276(7) of the SFA, or (6) as specified in Regulation 32.
Japan
The securities have not been and will not be registered under the Financial Instruments and Exchange Act of Japan (Act No. 25 of 1948, as amended), or the FIEA. The securities may not be
 
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offered or sold, directly or indirectly, in Japan or to or for the benefit of any resident of Japan (including any person resident in Japan or any corporation or other entity organized under the laws of Japan) or to others for reoffering or resale, directly or indirectly, in Japan or to or for the benefit of any resident of Japan, except pursuant to an exemption from the registration requirements of the FIEA and otherwise in compliance with any relevant laws and regulations of Japan.
We estimate that our share of the total expenses of the offering, excluding underwriting discounts and commissions, will be approximately $      .
We have agreed to indemnify the several underwriters against certain liabilities, including liabilities under the Securities Act of 1933.
The underwriters and their respective affiliates are full service financial institutions engaged in various activities, which may include sales and trading, commercial and investment banking, advisory, investment management, investment research, principal investment, hedging, market making, brokerage and other financial and non-financial activities and services. Certain of the underwriters and their respective affiliates have provided, and may in the future provide, a variety of these services to the issuer and to persons and entities with relationships with the issuer, for which they received or will receive customary fees and expenses.
In the ordinary course of their various business activities, the underwriters and their respective affiliates, officers, directors and employees may purchase, sell or hold a broad array of investments and actively trade securities, derivatives, loans, commodities, currencies, credit default swaps and other financial instruments for their own account and for the accounts of their customers, and such investment and trading activities may involve or relate to assets, securities and/or instruments of the issuer (directly, as collateral securing other obligations or otherwise) and/or persons and entities with relationships with the issuer. The underwriters and their respective affiliates may also communicate independent investment recommendations, market color or trading ideas and/or publish or express independent research views in respect of such assets, securities or instruments and may at any time hold, or recommend to clients that they should acquire, long and/or short positions in such assets, securities and instruments.
 
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Legal matters
The validity of the issuance of the shares of common stock offered by us in this offering will be passed upon for us by Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., Boston, Massachusetts. Ropes & Gray LLP, Boston, Massachusetts, is acting as counsel for the underwriters in connection with this offering.
Experts
Ernst & Young LLP, independent registered public accounting firm, has audited our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2019, as set forth in their report, which is incorporated by reference in this prospectus and elsewhere in the registration statement. Our financial statements are incorporated by reference in reliance on Ernst & Young LLP’s report, given on their authority as experts in accounting and auditing.
Where you can find more information
We are subject to the reporting requirements of the Exchange Act and file annual, quarterly and current reports, proxy statements and other information with the SEC. SEC filings are available at the SEC’s web site at http://www.sec.gov. We also maintain a website at http://www.quanterix.com, through which you can access our SEC filings. The information set forth on our website is not part of this prospectus supplement or the accompanying prospectus.
This prospectus supplement is part of a registration statement we filed with the SEC. This prospectus supplement and the accompanying prospectus omit some information contained in the registration statement in accordance with SEC rules and regulations. You should review the information and exhibits in the registration statement for further information on us and our consolidated subsidiaries and the securities we are offering. Statements in this prospectus supplement and the accompanying prospectus concerning any document we filed as an exhibit to the registration statement or that we otherwise filed with the SEC are not intended to be comprehensive and are qualified by reference to these filings. You should review the complete document to evaluate these statements. You can obtain a copy of the registration statement from the SEC’s website.
Incorporation by reference
The SEC allows us to “incorporate by reference” information that we file with them. Incorporation by reference allows us to disclose important information to you by referring you to those other documents. The information incorporated by reference is an important part of this prospectus supplement, and information that we file later with the SEC will automatically update and supersede this information. We filed a registration statement on Form S-3 under the Securities Act with the SEC with respect to the securities we may offer pursuant to this prospectus supplement. This prospectus supplement omits certain information contained in the registration statement, as permitted by the SEC. You should refer to the registration statement, including the exhibits, for further information about us and the securities we may offer pursuant to this prospectus supplement. Statements in this prospectus supplement regarding the provisions of certain documents filed with, or incorporated by reference in, the registration statement are not necessarily complete and each statement is qualified in all respects by that reference. Copies of all or any part of the registration statement, including the documents incorporated by reference or the exhibits, may be obtained upon payment of the prescribed rates at the offices of the SEC listed above in “Where you can find more information.” The documents we are incorporating by reference are:

our Annual Report on Form 10-K for the fiscal year ended December 31, 2019 that we filed with the SEC on March 13, 2020;

the portions of our definitive proxy statement on Schedule 14A that we filed with the SEC on April 29, 2020 that are deemed “filed” with the SEC under the Exchange Act;

our Quarterly Report on Form 10-Q for the fiscal quarter ended March 31, 2020 that we filed with the SEC on May 7, 2020, our Quarterly Report on Form 10-Q for the fiscal quarter ended
 
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June 30, 2020 that we filed with the SEC on August 5, 2020, and our Quarterly Report on Form 10-Q for the fiscal quarter ended September 30, 2020 that we filed with the SEC on November 9, 2020;

our Current Reports on Form 8-K that we filed with the SEC on June 26, 2020, August 4, 2020, August 6, 2020, August 7, 2020, August 11, 2020, August 18, 2020, October 5, 2020, and November 18, 2020 (in each case, except for information contained therein which is furnished rather than filed);

the description of our common stock contained in our Registration Statement on Form 8-A that we filed with the SEC on December 6, 2017, including any amendment or report filed for the purpose of updating such description; and

all reports and other documents subsequently filed by us pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act after the date of this prospectus supplement and prior to the termination or completion of the offering of securities under this prospectus supplement shall be deemed to be incorporated by reference in this prospectus supplement and to be a part hereof from the date of filing such reports and other documents.
The SEC file number for each of the documents listed above is 001-38319.
Any statement contained in this prospectus supplement or in a document incorporated or deemed to be incorporated by reference into this prospectus supplement will be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement or any other subsequently filed document that is deemed to be incorporated by reference into this prospectus supplement modifies or supersedes the statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement.
You may request, orally or in writing, a copy of any or all of the documents incorporated herein by reference. These documents will be provided to you at no cost, by contacting:
Quanterix Corporation
900 Middlesex Turnpike
Billerica, MA 01821
Attention: Investor Relations
Telephone: (617) 301-9400
You may also access these documents on our website, http://www.quanterix.com. The information contained on, or that can be accessed through, our website is not a part of this prospectus supplement or the accompanying prospectus. We have included our website address in this prospectus supplement solely as an inactive textual reference.
You should rely only on information contained in, or incorporated by reference into, this prospectus supplement and the accompanying prospectus. We have not authorized anyone to provide you with information different from that contained in this prospectus supplement or the accompanying prospectus or incorporated by reference in this prospectus supplement or the accompanying prospectus. We are not making offers to sell the securities in any jurisdiction in which such an offer or solicitation is not authorized or in which the person making such offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make such offer or solicitation.
 
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PROSPECTUS
Quanterix Corporation
COMMON STOCK
PREFERRED STOCK
DEBT SECURITIES
WARRANTS
RIGHTS
UNITS
This prospectus will allow us to offer and sell, from time to time in one or more offerings, any combination of the securities described in this prospectus, either individually or in units. We may also offer common stock or preferred stock upon conversion of or exchange for the debt securities; common stock upon conversion of or exchange for the preferred stock; or common stock, preferred stock or debt securities upon the exercise of warrants or rights.
This prospectus describes the general terms of these securities and the general manner in which these securities will be offered. We will provide you with the specific terms of any offering in one or more supplements to this prospectus. The prospectus supplements will also describe the specific manner in which these securities will be offered and may also supplement, update or amend information contained in this document. You should read this prospectus and any prospectus supplement, as well as any documents incorporated by reference into this prospectus or any prospectus supplement, carefully before you invest.
Our securities may be sold directly by us to you, through agents designated from time to time or to or through underwriters or dealers. For additional information on the methods of sale, you should refer to the section entitled “Plan of Distribution” in this prospectus and in the applicable prospectus supplement. If any underwriters or agents are involved in the sale of our securities with respect to which this prospectus is being delivered, the names of such underwriters or agents and any applicable fees, commissions or discounts and over-allotment options will be set forth in a prospectus supplement. The price to the public of such securities and the net proceeds that we expect to receive from such sale will also be set forth in a prospectus supplement.
Our common stock is listed on The Nasdaq Global Market under the symbol “QTRX.” On November 5, 2020, the last reported sale price of our common stock was $44.09 per share. The applicable prospectus supplement will contain information, where applicable, as to any other listing, if any, on The Nasdaq Global Market or any securities market or other securities exchange of the securities covered by the prospectus supplement. Prospective purchasers of our securities are urged to obtain current information as to the market prices of our securities, where applicable.
Investing in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you should consider carefully the risks that we have described on page 4 of this prospectus under the caption “Risk Factors.” We may include specific risk factors in supplements to this prospectus under the caption “Risk Factors.” This prospectus may not be used to sell our securities unless accompanied by a prospectus supplement.
Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.
The date of this prospectus is November 6, 2020.
 

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ABOUT THIS PROSPECTUS
This prospectus is part of an automatic shelf registration statement on Form S-3 that we filed with the Securities and Exchange Commission, or SEC, as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act of 1933, as amended, or the Securities Act. Under this shelf registration process, we may offer shares of our common stock and preferred stock, various series of debt securities and/or warrants or rights to purchase any of such securities, either individually or in units, in one or more offerings, at prices and on terms to be set forth in one or more supplements to this prospectus at the time of an offering. This prospectus provides you with a general description of the securities we may offer. Each time we offer a type or series of securities under this prospectus, we will provide a prospectus supplement that will contain specific information about the terms of that offering.
This prospectus does not contain all of the information included in the registration statement. For a more complete understanding of the offering of the securities, you should refer to the registration statement, including its exhibits. The prospectus supplement may also add, update or change information contained or incorporated by reference in this prospectus. However, no prospectus supplement will offer a security that is not registered and described in this prospectus. This prospectus, together with the applicable prospectus supplements and the documents incorporated by reference into this prospectus, includes all material information relating to the offering of securities under this prospectus. You should carefully read this prospectus, the applicable prospectus supplement, the information and documents incorporated herein by reference and the additional information under the heading “Where You Can Find More Information” before making an investment decision.
You should rely only on the information we have provided or incorporated by reference in this prospectus or any prospectus supplement. We have not authorized anyone to provide you with information different from that contained or incorporated by reference in this prospectus. No dealer, salesperson or other person is authorized to give any information or to represent anything not contained or incorporated by reference in this prospectus. You must not rely on any unauthorized information or representation. This prospectus is an offer to sell only the securities offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so. You should assume that the information in this prospectus or any prospectus supplement is accurate only as of the date on the front of the document and that any information we have incorporated herein by reference is accurate only as of the date of the document incorporated by reference, regardless of the time of delivery of this prospectus or any sale of a security.
We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference in the accompanying prospectus were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.
This prospectus may not be used to consummate sales of our securities, unless it is accompanied by a prospectus supplement. To the extent there are inconsistencies between any prospectus supplement, this prospectus and any documents incorporated by reference, the document with the most recent date will control.
Unless the context otherwise requires, “Quanterix,” “QTRX,” “the Company,” “we,” “us,” “our” and similar terms refer to Quanterix Corporation and our subsidiaries.
All brand names or trademarks appearing in this prospectus are the property of their respective holders. Use or display by us of other parties’ trademarks, trade dress, or products in this prospectus is not intended to, and does not, imply a relationship with, or endorsements or sponsorship of, us by the trademark or trade dress owners.
 
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PROSPECTUS SUMMARY
The following is a summary of what we believe to be the most important aspects of our business and the offering of our securities under this prospectus. We urge you to read this entire prospectus, including the more detailed consolidated financial statements, notes to the consolidated financial statements and other information incorporated by reference from our other filings with the SEC or included in any applicable prospectus supplement. Investing in our securities involves risks. Therefore, carefully consider the risk factors set forth in any prospectus supplements and in our most recent annual and quarterly filings with the SEC, as well as other information in this prospectus and any prospectus supplements and the documents incorporated by reference herein or therein, before purchasing our securities. Each of the risk factors could adversely affect our business, operating results and financial condition, as well as adversely affect the value of an investment in our securities.
About Quanterix Corporation
Quanterix is a life sciences company that has developed next generation, ultra-sensitive digital immunoassay platforms that advance precision health for life sciences research and diagnostics. Quanterix’s platforms are based on its proprietary digital “Simoa” detection technology. Quanterix’s Simoa bead-based and planar array platforms enable customers to reliably detect protein biomarkers in extremely low concentrations in blood, serum and other fluids that, in many cases, are undetectable using conventional, analog immunoassay technologies, and also allow researchers to define and validate the function of novel protein biomarkers that are only present in very low concentrations and have been discovered using technologies such as mass spectrometry.
Additional Information
For additional information related to our business and operations, please refer to the reports incorporated herein by reference, as described under the caption “Incorporation of Documents by Reference” on page 25 of this prospectus.
Our Corporate Information
We were originally incorporated in the State of Delaware in April 2007 under the name “Digital Genomics, Inc.” In August 2007, we changed our name to “Quanterix Corporation.” Our principal executive offices are located at 900 Middlesex Turnpike, Billerica, Massachusetts 01821, and our telephone number is (617) 301-9400. We maintain a website at www.quanterix.com, to which we regularly post copies of our press releases as well as additional information about us. The information contained on, or that can be accessed through, our website is not a part of this prospectus. We have included our website address in this prospectus solely as an inactive textual reference.
Offerings Under This Prospectus
Under this prospectus, we may offer shares of our common stock and preferred stock, various series of debt securities and/or warrants or rights to purchase any of such securities, either individually or in units, from time to time at prices and on terms to be determined by market conditions at the time of the offering. This prospectus provides you with a general description of the securities we may offer. Each time we offer a type or series of securities under this prospectus, we will provide a prospectus supplement that will describe the specific amounts, prices and other important terms of the securities, including, to the extent applicable:

designation or classification;

aggregate principal amount or aggregate offering price;

maturity, if applicable;

rates and times of payment of interest or dividends, if any;

redemption, conversion or sinking fund terms, if any;

voting or other rights, if any; and

conversion or exercise prices, if any.
 
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The prospectus supplement also may add, update or change information contained in this prospectus or in documents we have incorporated by reference into this prospectus. However, no prospectus supplement will fundamentally change the terms that are set forth in this prospectus or offer a security that is not registered and described in this prospectus.
We may sell the securities directly to investors or to or through agents, underwriters or dealers. We, and our agents or underwriters, reserve the right to accept or reject all or part of any proposed purchase of securities. If we offer securities through agents or underwriters, we will include in the applicable prospectus supplement:

the names of those agents or underwriters;

applicable fees, discounts and commissions to be paid to them;

details regarding over-allotment options, if any; and

the net proceeds to us.
This prospectus may not be used to consummate a sale of any securities unless it is accompanied by a prospectus supplement.
 
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RISK FACTORS
Investing in our securities involves significant risk. The prospectus supplement applicable to each offering of our securities will contain a discussion of the risks applicable to an investment in Quanterix. Prior to making a decision about investing in our securities, you should carefully consider the specific factors discussed under the heading “Risk Factors” in the applicable prospectus supplement, together with all of the other information contained or incorporated by reference in the prospectus supplement or appearing or incorporated by reference in this prospectus. You should also consider the risks, uncertainties and assumptions discussed under the heading “Risk Factors” included in our most recent annual report on Form 10-K, as revised or supplemented by our subsequent quarterly reports on Form 10-Q or our current reports on Form 8-K that we have filed with the SEC, all of which are incorporated herein by reference, and which may be amended, supplemented or superseded from time to time by other reports we file with the SEC in the future. The risks and uncertainties we have described are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our operations. The occurrence of any of these risks might cause you to lose all or part of your investment in the offered securities.
 
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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS
This prospectus and the documents incorporated by reference in this prospectus include forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act, that relate to future events or our future financial performance and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to differ materially from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Words such as, but not limited to, “believe,” “expect,” “anticipate,” “estimate,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “targets,” “likely,” “will,” “would,” “could,” “should,” “continue,” and similar expressions or phrases, or the negative of those expressions or phrases, are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Although we believe that we have a reasonable basis for each forward-looking statement contained in this prospectus and incorporated by reference in this prospectus, we caution you that these statements are based on our projections of the future that are subject to known and unknown risks and uncertainties and other factors that may cause our actual results, level of activity, performance or achievements expressed or implied by these forward-looking statements, to differ. The sections in our periodic reports, including our Annual Report on Form 10-K for the fiscal year ended December 31, 2019, entitled “Business,” “Risk Factors,” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” as well as other sections in this prospectus and the documents or reports incorporated by reference in this prospectus, discuss some of the factors that could contribute to these differences. These forward-looking statements include, among other things, statements about:

the implementation of our business model and strategic plans for our business, products and services;

the potential size of the markets and fields addressable by our Simoa technology platforms;

the commercialization and adoption of our existing products and services and the success of our new product offerings;

our ability to develop additional assays, including multiplexed assays;

the accuracy of our estimates regarding expenses, future revenues, capital requirements and our needs for additional financing;

the ability of our Simoa technology’s sensitivity to improve existing diagnostics and to enable the development of new diagnostic tests and tools;

the potential of our Simoa technology in the field of companion diagnostics and its adoption by healthcare professionals;

the impact of our Simoa technology on proteomic research;

the usefulness of the data generated by our Simoa technology in the life science research, diagnostic and precision health screening fields; and

our financial performance.
We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. We have included important cautionary statements in this prospectus or in the documents incorporated by reference in this prospectus, particularly in the “Risk Factors” section, that we believe could cause actual results or events to differ materially from the forward-looking statements that we make. For a summary of such factors, please refer to the section entitled “Risk Factors” in this prospectus, as updated and supplemented by the discussion of risks and uncertainties under “Risk Factors” contained in any supplements to this prospectus and in our most recent annual report on Form 10-K, as revised or supplemented by our subsequent quarterly reports on Form 10-Q or our current reports on Form 8-K, as well as any amendments thereto, as filed with the SEC and which are incorporated herein by reference. The information contained in this document is believed to be current as of the date of this document. We do not
 
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intend to update any of the forward-looking statements after the date of this document to conform these statements to actual results or to changes in our expectations, except as required by law.
In light of these assumptions, risks and uncertainties, the results and events discussed in the forward-looking statements contained in this prospectus or in any document incorporated herein by reference might not occur. Investors are cautioned not to place undue reliance on the forward-looking statements, which speak only as of the date of this prospectus or the date of the document incorporated by reference in this prospectus. We are not under any obligation, and we expressly disclaim any obligation, to update or alter any forward-looking statements, whether as a result of new information, future events or otherwise. All subsequent forward-looking statements attributable to us or to any person acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this section.
 
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USE OF PROCEEDS
Unless otherwise indicated in the applicable prospectus supplement, we intend to use any net proceeds from the sale of securities under this prospectus (1) to expand our life sciences commercial operations to grow and support the installed base of our products among life sciences customers in the United States and internationally; (2) to improve and update our Simoa technology and instruments and to develop additional assays; (3) to potentially pursue regulatory approvals or clearances to develop instruments, assay kits and consumables in areas outside of life science research and, subject to receipt of such necessary regulatory approvals or clearances, to develop such instruments, assay kits and consumables; (4) to potentially pursue acquisitions or other business development opportunities; and (5) for working capital and other general corporate purposes, including, but not limited to, capital expenditures, investments, and collaborations. We have not determined the amounts we plan to spend on any of the areas listed above or the timing of these expenditures. As a result, our management will have broad discretion to allocate the net proceeds, if any, we receive in connection with securities offered pursuant to this prospectus for any purpose. Additional information on the use of net proceeds from the sale of securities covered by this prospectus may be set forth in the prospectus supplement relating to the specific offering. Pending application of the net proceeds as described above, we may initially invest the net proceeds in short-term, investment-grade, interest-bearing securities or apply them to the reduction of short-term indebtedness.
 
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PLAN OF DISTRIBUTION
We may offer securities under this prospectus from time to time pursuant to underwritten public offerings, negotiated transactions, block trades or a combination of these methods. We may sell the securities (1) through underwriters or dealers, (2) through agents or (3) directly to one or more purchasers, or through a combination of such methods. We may distribute the securities from time to time in one or more transactions at:

a fixed price or prices, which may be changed from time to time;

market prices prevailing at the time of sale;

prices related to the prevailing market prices; or

negotiated prices.
We may directly solicit offers to purchase the securities being offered by this prospectus. We may also designate agents to solicit offers to purchase the securities from time to time, and may enter into arrangements for “at-the-market,” equity line or similar transactions. We will name in a prospectus supplement any underwriter or agent involved in the offer or sale of the securities.
If we utilize a dealer in the sale of the securities being offered by this prospectus, we will sell the securities to the dealer, as principal. The dealer may then resell the securities to the public at varying prices to be determined by the dealer at the time of resale.
If we utilize an underwriter in the sale of the securities being offered by this prospectus, we will execute an underwriting agreement with the underwriter at the time of sale, and we will provide the name of any underwriter in the prospectus supplement which the underwriter will use to make resales of the securities to the public. In connection with the sale of the securities, we, or the purchasers of the securities for whom the underwriter may act as agent, may compensate the underwriter in the form of underwriting discounts or commissions. The underwriter may sell the securities to or through dealers, and the underwriter may compensate those dealers in the form of discounts, concessions or commissions.
With respect to underwritten public offerings, negotiated transactions and block trades, we will provide in the applicable prospectus supplement information regarding any compensation we pay to underwriters, dealers or agents in connection with the offering of the securities, and any discounts, concessions or commissions allowed by underwriters to participating dealers. Underwriters, dealers and agents participating in the distribution of the securities may be deemed to be underwriters within the meaning of the Securities Act, and any discounts and commissions received by them and any profit realized by them on resale of the securities may be deemed to be underwriting discounts and commissions. We may enter into agreements to indemnify underwriters, dealers and agents against civil liabilities, including liabilities under the Securities Act, or to contribute to payments they may be required to make in respect thereof.
If so indicated in the applicable prospectus supplement, we will authorize underwriters, dealers or other persons acting as our agents to solicit offers by certain institutions to purchase securities from us pursuant to delayed delivery contracts providing for payment and delivery on the date stated in each applicable prospectus supplement. Each contract will be for an amount not less than, and the aggregate amount of securities sold pursuant to such contracts shall not be less nor more than, the respective amounts stated in each applicable prospectus supplement. Institutions with whom the contracts, when authorized, may be made include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and other institutions, but shall in all cases be subject to our approval. Delayed delivery contracts will not be subject to any conditions except that:

the purchase by an institution of the securities covered under that contract shall not at the time of delivery be prohibited under the laws of the jurisdiction to which that institution is subject; and

if the securities are also being sold to underwriters acting as principals for their own account, the underwriters shall have purchased such securities not sold for delayed delivery. The underwriters and other persons acting as our agents will not have any responsibility in respect of the validity or performance of delayed delivery contracts.
 
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One or more firms, referred to as “remarketing firms,” may also offer or sell the securities, if a prospectus supplement so indicates, in connection with a remarketing arrangement upon their purchase. Remarketing firms will act as principals for their own accounts or as our agents. These remarketing firms will offer or sell the securities in accordance with the terms of the securities. Each prospectus supplement will identify and describe any remarketing firm and the terms of its agreement, if any, with us and will describe the remarketing firm’s compensation. Remarketing firms may be deemed to be underwriters in connection with the securities they remarket. Remarketing firms may be entitled under agreements that may be entered into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, and may be customers of, engage in transactions with or perform services for us in the ordinary course of business.
Certain underwriters may use this prospectus and any accompanying prospectus supplement for offers and sales related to market-making transactions in the securities. These underwriters may act as principal or agent in these transactions, and the sales will be made at prices related to prevailing market prices at the time of sale. Any underwriters involved in the sale of the securities may qualify as “underwriters” within the meaning of Section 2(a)(11) of the Securities Act. In addition, the underwriters’ commissions, discounts or concessions may qualify as underwriters’ compensation under the Securities Act and the rules of the Financial Industry Regulatory Authority, Inc., or FINRA.
Shares of our common stock sold pursuant to the registration statement of which this prospectus is a part will be authorized for listing and trading on The Nasdaq Global Market. The applicable prospectus supplement will contain information, where applicable, as to any other listing, if any, on The Nasdaq Global Market or any securities market or other securities exchange of the securities covered by the prospectus supplement. Underwriters may make a market in our common stock, but will not be obligated to do so and may discontinue any market making at any time without notice. We can make no assurance as to the liquidity of or the existence, development or maintenance of trading markets for any of the securities.
In order to facilitate the offering of the securities, certain persons participating in the offering may engage in transactions that stabilize, maintain or otherwise affect the price of the securities. This may include over-allotments or short sales of the securities, which involve the sale by persons participating in the offering of more securities than we sold to them. In these circumstances, these persons would cover such over-allotments or short positions by making purchases in the open market or by exercising their over-allotment option. In addition, these persons may stabilize or maintain the price of the securities by bidding for or purchasing the applicable security in the open market or by imposing penalty bids, whereby selling concessions allowed to dealers participating in the offering may be reclaimed if the securities sold by them are repurchased in connection with stabilization transactions. The effect of these transactions may be to stabilize or maintain the market price of the securities at a level above that which might otherwise prevail in the open market. These transactions may be discontinued at any time.
The underwriters, dealers and agents may engage in other transactions with us, or perform other services for us, in the ordinary course of their business.
 
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DESCRIPTION OF COMMON STOCK
We are authorized to issue 120,000,000 shares of common stock, par value $0.001 per share. As of September 30, 2020, we had 31,583,509 shares of common stock outstanding and approximately 40 stockholders of record.
The following summary of certain provisions of our common stock does not purport to be complete. You should refer to the section of this prospectus entitled “Certain Provisions of Delaware Law and of the Company’s Certificate of Incorporation and Bylaws” and our amended and restated certificate of incorporation, or the restated certificate of incorporation, and our restated bylaws, both of which are included as exhibits to the registration statement of which this prospectus is a part. The summary below is also qualified by provisions of applicable law.
General
Holders of our common stock are entitled to one vote for each share held on all matters submitted to a vote of stockholders and do not have cumulative voting rights. An election of directors by our stockholders shall be determined by a plurality of the votes cast by the stockholders entitled to vote on the election. Holders of common stock are entitled to receive proportionately any dividends as may be declared by our Board of Directors, subject to any preferential dividend rights of any series of preferred stock that we may designate and issue in the future. All shares of common stock outstanding as of the date of this prospectus and, upon issuance and sale, all shares of common stock that we may offer pursuant to this prospectus, will be fully paid and nonassessable.
In the event of our liquidation or dissolution, the holders of common stock are entitled to receive proportionately our net assets available for distribution to stockholders after the payment of all debts and other liabilities and subject to the prior rights of any outstanding preferred stock. Holders of common stock have no preemptive, subscription, redemption or conversion rights. There are no redemption or sinking fund provisions applicable to the common stock. Our outstanding shares of common stock are validly issued, fully paid and nonassessable. The rights, preferences and privileges of holders of common stock are subject to and may be adversely affected by the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future.
Transfer Agent and Registrar
The transfer agent and registrar for our common stock is Computershare Trust Company, N.A., with offices at 250 Royall Street, Canton, Massachusetts 02021.
Stock Exchange Listing
Our common stock is listed for quotation on The Nasdaq Global Market under the symbol “QTRX.”
 
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DESCRIPTION OF PREFERRED STOCK
The following description of preferred stock and the description of the terms of any particular series of preferred stock that we choose to issue hereunder are not complete. These descriptions are qualified in their entirety by reference to our restated certificate of incorporation and the certificate of designation relating to any series of preferred stock issued by us. The rights, preferences, privileges and restrictions of the preferred stock of each series will be fixed by the certificate of designation relating to that series.
We currently have no shares of preferred stock outstanding. Our Board of Directors has the authority, without further action by the stockholders, to issue up to 5,000,000 shares of preferred stock in one or more series and to fix the rights, preferences, privileges and restrictions granted to or imposed upon the preferred stock. Any or all of these rights may be greater than the rights of our common stock.
Our Board of Directors, without stockholder approval, can issue preferred stock with voting, conversion or other rights that could negatively affect the voting power and other rights of the holders of our common stock. Preferred stock could thus be issued quickly with terms calculated to delay or prevent a change in control or make it more difficult to remove our management. Additionally, the issuance of preferred stock may have the effect of decreasing the market price of our common stock.
Our Board of Directors may specify the following characteristics of any preferred stock:

the maximum number of shares;

the designation of the shares;

the annual dividend rate, if any, whether the dividend rate is fixed or variable, the date or dates on which dividends will accrue, the dividend payment dates, and whether dividends will be cumulative;

the price and the terms and conditions for redemption, if any, including redemption at the option of us or at the option of the holders, including the time period for redemption, and any accumulated dividends or premiums;

the liquidation preference, if any, and any accumulated dividends upon the liquidation, dissolution or winding up of our affairs;

any sinking fund or similar provision, and, if so, the terms and provisions relating to the purpose and operation of the fund;

the terms and conditions, if any, for conversion or exchange of shares of any other class or classes of our capital stock or any series of any other class or classes, or of any other series of the same class, or any other securities or assets, including the price or the rate of conversion or exchange and the method, if any, of adjustment;

the voting rights;

any or all other preferences and relative, participating, optional or other special rights, privileges or qualifications, limitations or restrictions; and

any preferred stock issued will be fully paid and nonassessable upon issuance.
Transfer Agent and Registrar
The transfer agent and registrar for our preferred stock will be set forth in the applicable prospectus supplement.
 
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DESCRIPTION OF DEBT SECURITIES
The following description, together with the additional information we include in any applicable prospectus supplements, summarizes the material terms and provisions of the debt securities that we may offer under this prospectus. While the terms we have summarized below will apply generally to any future debt securities we may offer pursuant to this prospectus, we will describe the particular terms of any debt securities that we may offer in more detail in the applicable prospectus supplement. If we so indicate in a prospectus supplement, the terms of any debt securities offered under such prospectus supplement may differ from the terms we describe below, and to the extent the terms set forth in a prospectus supplement differ from the terms described below, the terms set forth in the prospectus supplement shall control.
We may sell from time to time, in one or more offerings under this prospectus, debt securities, which may be senior or subordinated. We will issue any such senior debt securities under a senior indenture that we will enter into with a trustee to be named in the senior indenture. We will issue any such subordinated debt securities under a subordinated indenture, which we will enter into with a trustee to be named in the subordinated indenture. We have filed forms of these documents as exhibits to the registration statement, of which this prospectus is a part. We use the term “indentures” to refer to either the senior indenture or the subordinated indenture, as applicable. The indentures will be qualified under the Trust Indenture Act of 1939, or the Trust Indenture Act, as in effect on the date of the indenture. We use the term “debenture trustee” to refer to either the trustee under the senior indenture or the trustee under the subordinated indenture, as applicable.
The following summaries of material provisions of the senior debt securities, the subordinated debt securities and the indentures are subject to, and qualified in their entirety by reference to, all the provisions of the indenture applicable to a particular series of debt securities.
General
Each indenture provides that debt securities may be issued from time to time in one or more series and may be denominated and payable in foreign currencies or units based on or relating to foreign currencies. Neither indenture limits the amount of debt securities that may be issued thereunder, and each indenture provides that the specific terms of any series of debt securities shall be set forth in, or determined pursuant to, an authorizing resolution and/or a supplemental indenture, if any, relating to such series.
We will describe in each prospectus supplement the following terms relating to a series of debt securities:

the title or designation;

the aggregate principal amount and any limit on the amount that may be issued;

the currency or units based on or relating to currencies in which debt securities of such series are denominated and the currency or units in which principal or interest or both will or may be payable;

whether we will issue the series of debt securities in global form, the terms of any global securities and who the depositary will be;

the maturity date and the date or dates on which principal will be payable;

the interest rate, which may be fixed or variable, or the method for determining the rate and the date interest will begin to accrue, the date or dates interest will be payable and the record dates for interest payment dates or the method for determining such dates;

whether or not the debt securities will be secured or unsecured, and the terms of any secured debt;

the terms of the subordination of any series of subordinated debt;

the place or places where payments will be payable;

our right, if any, to defer payment of interest and the maximum length of any such deferral period;

the date, if any, after which, and the price at which, we may, at our option, redeem the series of debt securities pursuant to any optional redemption provisions;
 
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the date, if any, on which, and the price at which we are obligated, pursuant to any mandatory sinking fund provisions or otherwise, to redeem, or at the holder’s option to purchase, the series of debt securities;

whether the indenture will restrict our ability to pay dividends, or will require us to maintain any asset ratios or reserves;

whether we will be restricted from incurring any additional indebtedness;

a discussion of any material or special U.S. federal income tax considerations applicable to a series of debt securities;

the denominations in which we will issue the series of debt securities, if other than denominations of $1,000 and any integral multiple thereof; and

any other specific terms, preferences, rights or limitations of, or restrictions on, the debt securities.
We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture. We will provide you with information on the federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.
Conversion or Exchange Rights
We will set forth in the prospectus supplement the terms, if any, on which a series of debt securities may be convertible into or exchangeable for our common stock or our other securities. We will include provisions as to whether conversion or exchange is mandatory, at the option of the holder or at our option. We may include provisions pursuant to which the number of shares of our common stock or our other securities that the holders of the series of debt securities receive would be subject to adjustment.
Consolidation, Merger or Sale; No Protection in Event of a Change of Control or Highly Leveraged Transaction
The indentures do not contain any covenant that restricts our ability to merge or consolidate, or sell, convey, transfer or otherwise dispose of all or substantially all of our assets. However, any successor to or acquirer of such assets must assume all of our obligations under the indentures or the debt securities, as appropriate.
Unless we state otherwise in the applicable prospectus supplement, the debt securities will not contain any provisions that may afford holders of the debt securities protection in the event we have a change of control or in the event of a highly leveraged transaction (whether or not such transaction results in a change of control), which could adversely affect holders of debt securities.
Events of Default Under the Indenture
The following are events of default under the indentures with respect to any series of debt securities that we may issue:

if we fail to pay interest when due and our failure continues for 90 days and the time for payment has not been extended or deferred;

if we fail to pay the principal, or premium, if any, when due and the time for payment has not been extended or delayed;

if we fail to observe or perform any other covenant set forth in the debt securities of such series or the applicable indentures, other than a covenant specifically relating to and for the benefit of holders of another series of debt securities, and our failure continues for 90 days after we receive written notice from the debenture trustee or holders of not less than a majority in aggregate principal amount of the outstanding debt securities of the applicable series; and

if specified events of bankruptcy, insolvency or reorganization occur as to us.
No event of default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an event of default with respect to any
 
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other series of debt securities. The occurrence of an event of default may constitute an event of default under any bank credit agreements we may have in existence from time to time. In addition, the occurrence of certain events of default or an acceleration under the indenture may constitute an event of default under certain of our other indebtedness outstanding from time to time.
If an event of default with respect to debt securities of any series at the time outstanding occurs and is continuing, then the trustee or the holders of not less than a majority in principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the debenture trustee if given by the holders), declare to be due and payable immediately the principal (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) of and premium and accrued and unpaid interest, if any, on all debt securities of that series. Before a judgment or decree for payment of the money due has been obtained with respect to debt securities of any series, the holders of a majority in principal amount of the outstanding debt securities of that series (or, at a meeting of holders of such series at which a quorum is present, the holders of a majority in principal amount of the debt securities of such series represented at such meeting) may rescind and annul the acceleration if all events of default, other than the non-payment of accelerated principal, premium, if any, and interest, if any, with respect to debt securities of that series, have been cured or waived as provided in the applicable indenture (including payments or deposits in respect of principal, premium or interest that had become due other than as a result of such acceleration). We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of such discount securities upon the occurrence of an event of default.
Subject to the terms of the indentures, if an event of default under an indenture shall occur and be continuing, the debenture trustee will be under no obligation to exercise any of its rights or powers under such indenture at the request or direction of any of the holders of the applicable series of debt securities, unless such holders have offered the debenture trustee reasonable indemnity. The holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the debenture trustee, or exercising any trust or power conferred on the debenture trustee, with respect to the debt securities of that series, provided that:

the direction so given by the holder is not in conflict with any law or the applicable indenture; and

subject to its duties under the Trust Indenture Act, the debenture trustee need not take any action that might involve it in personal liability or might be unduly prejudicial to the holders not involved in the proceeding.
A holder of the debt securities of any series will only have the right to institute a proceeding under the indentures or to appoint a receiver or trustee, or to seek other remedies if:

the holder previously has given written notice to the debenture trustee of a continuing event of default with respect to that series;

the holders of at least a majority in aggregate principal amount of the outstanding debt securities of that series have made written request, and such holders have offered reasonable indemnity to the debenture trustee to institute the proceeding as trustee; and

the debenture trustee does not institute the proceeding, and does not receive from the holders of a majority in aggregate principal amount of the outstanding debt securities of that series (or at a meeting of holders of such series at which a quorum is present, the holders of a majority in principal amount of the debt securities of such series represented at such meeting) other conflicting directions within 60 days after the notice, request and offer.
These limitations do not apply to a suit instituted by a holder of debt securities if we default in the payment of the principal, premium, if any, or interest on, the debt securities.
We will periodically file statements with the applicable debenture trustee regarding our compliance with specified covenants in the applicable indenture.
 
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Modification of Indenture; Waiver
The debenture trustee and we may change the applicable indenture without the consent of any holders with respect to specific matters, including:

to fix any ambiguity, defect or inconsistency in the indenture; and

to change anything that does not materially adversely affect the interests of any holder of debt securities of any series issued pursuant to such indenture.
In addition, under the indentures, the rights of holders of a series of debt securities may be changed by us and the debenture trustee with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series (or, at a meeting of holders of such series at which a quorum is present, the holders of a majority in principal amount of the debt securities of such series represented at such meeting) that is affected. However, the debenture trustee and we may make the following changes only with the consent of each holder of any outstanding debt securities affected:

extending the fixed maturity of the series of debt securities;

reducing the principal amount, reducing the rate of or extending the time of payment of interest, or any premium payable upon the redemption of any debt securities;

reducing the principal amount of discount securities payable upon acceleration of maturity;

making the principal of or premium or interest on any debt security payable in currency other than that stated in the debt security; or

reducing the percentage of debt securities, the holders of which are required to consent to any amendment or waiver.
Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of any series (or, at a meeting of holders of such series at which a quorum is present, the holders of a majority in principal amount of the debt securities of such series represented at such meeting) may on behalf of the holders of all debt securities of that series waive our compliance with provisions of the indenture. The holders of a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all the debt securities of such series waive any past default under the indenture with respect to that series and its consequences, except a default in the payment of the principal of, premium or any interest on any debt security of that series or in respect of a covenant or provision, which cannot be modified or amended without the consent of the holder of each outstanding debt security of the series affected; provided, however, that the holders of a majority in principal amount of the outstanding debt securities of any series may rescind an acceleration and its consequences, including any related payment default that resulted from the acceleration.
Discharge
Each indenture provides that we can elect to be discharged from our obligations with respect to one or more series of debt securities, except for obligations to:

the transfer or exchange of debt securities of the series;

replace stolen, lost or mutilated debt securities of the series;

maintain paying agencies;

hold monies for payment in trust;

compensate and indemnify the trustee; and

appoint any successor trustee.
In order to exercise our rights to be discharged with respect to a series, we must deposit with the trustee money or government obligations sufficient to pay all the principal of, the premium, if any, and interest on, the debt securities of the series on the dates payments are due.
 
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Form, Exchange, and Transfer
We will issue the debt securities of each series only in fully registered form without coupons and, unless we otherwise specify in the applicable prospectus supplement, in denominations of $1,000 and any integral multiple thereof. The indentures provide that we may issue debt securities of a series in temporary or permanent global form and as book-entry securities that will be deposited with, or on behalf of, The Depository Trust Company or another depositary named by us and identified in a prospectus supplement with respect to that series.
At the option of the holder, subject to the terms of the indentures and the limitations applicable to global securities described in the applicable prospectus supplement, the holder of the debt securities of any series can exchange the debt securities for other debt securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount.
Subject to the terms of the indentures and the limitations applicable to global securities set forth in the applicable prospectus supplement, holders of the debt securities may present the debt securities for exchange or for registration of transfer, duly endorsed or with the form of transfer endorsed thereon duly executed if so required by us or the security registrar, at the office of the security registrar or at the office of any transfer agent designated by us for this purpose. Unless otherwise provided in the debt securities that the holder presents for transfer or exchange or in the applicable indenture, we will make no service charge for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges.
We will name in the applicable prospectus supplement the security registrar, and any transfer agent in addition to the security registrar, that we initially designate for any debt securities. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.
If we elect to redeem the debt securities of any series, we will not be required to:

issue, register the transfer of, or exchange any debt securities of that series during a period beginning at the opening of business 15 days before the day of mailing of a notice of redemption of any debt securities that may be selected for redemption and ending at the close of business on the day of the mailing; or

register the transfer of or exchange any debt securities so selected for redemption, in whole or in part, except the unredeemed portion of any debt securities we are redeeming in part.
Information Concerning the Debenture Trustee
The debenture trustee, other than during the occurrence and continuance of an event of default under the applicable indenture, undertakes to perform only those duties as are specifically set forth in the applicable indenture. Upon an event of default under an indenture, the debenture trustee under such indenture must use the same degree of care as a prudent person would exercise or use in the conduct of his or her own affairs. Subject to this provision, the debenture trustee is under no obligation to exercise any of the powers given it by the indentures at the request of any holder of debt securities unless it is offered reasonable security and indemnity against the costs, expenses and liabilities that it might incur.
Payment and Paying Agents
Unless we otherwise indicate in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities, or one or more predecessor securities, are registered at the close of business on the regular record date for the interest.
We will pay principal of and any premium and interest on the debt securities of a particular series at the office of the paying agents designated by us, except that unless we otherwise indicate in the applicable prospectus supplement, we will make interest payments by check which we will mail to the holder. Unless we otherwise indicate in a prospectus supplement, we will designate the corporate trust office of the debenture trustee in the City of New York as our sole paying agent for payments with respect to debt securities of each
 
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series. We will name in the applicable prospectus supplement any other paying agents that we initially designate for the debt securities of a particular series. We will maintain a paying agent in each place of payment for the debt securities of a particular series.
All money we pay to a paying agent or the debenture trustee for the payment of the principal of or any premium or interest on any debt securities which remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us, and the holder of the security thereafter may look only to us for payment thereof.
Governing Law
The indentures and the debt securities will be governed by and construed in accordance with the laws of the State of New York, except to the extent that the Trust Indenture Act is applicable.
Subordination of Subordinated Debt Securities
Our obligations pursuant to any subordinated debt securities will be unsecured and will be subordinate and junior in priority of payment to certain of our other indebtedness to the extent described in a prospectus supplement. The subordinated indenture does not limit the amount of senior indebtedness we may incur. It also does not limit us from issuing any other secured or unsecured debt.
 
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DESCRIPTION OF WARRANTS
General
We may issue warrants to purchase shares of our common stock, preferred stock and/or debt securities in one or more series together with other securities or separately, as described in the applicable prospectus supplement. Below is a description of certain general terms and provisions of the warrants that we may offer. Particular terms of the warrants will be described in the warrant agreements and the prospectus supplement relating to the warrants.
The applicable prospectus supplement will contain, where applicable, the following terms of and other information relating to the warrants:

the specific designation and aggregate number of, and the price at which we will issue, the warrants;

the currency or currency units in which the offering price, if any, and the exercise price are payable;

the designation, amount and terms of the securities purchasable upon exercise of the warrants;

if applicable, the exercise price for shares of our common stock and the number of shares of common stock to be received upon exercise of the warrants;

if applicable, the exercise price for shares of our preferred stock, the number of shares of preferred stock to be received upon exercise, and a description of that series of our preferred stock;

if applicable, the exercise price for our debt securities, the amount of debt securities to be received upon exercise, and a description of that series of debt securities;

the date on which the right to exercise the warrants will begin and the date on which that right will expire or, if you may not continuously exercise the warrants throughout that period, the specific date or dates on which you may exercise the warrants;

whether the warrants will be issued in fully registered form or bearer form, in definitive or global form or in any combination of these forms, although, in any case, the form of a warrant included in a unit will correspond to the form of the unit and of any security included in that unit;

any applicable material U.S. federal income tax consequences;

the identity of the warrant agent for the warrants and of any other depositaries, execution or paying agents, transfer agents, registrars or other agents;

the proposed listing, if any, of the warrants or any securities purchasable upon exercise of the warrants on any securities exchange;

if applicable, the date from and after which the warrants and the common stock, preferred stock and/or debt securities will be separately transferable;

if applicable, the minimum or maximum amount of the warrants that may be exercised at any one time;

information with respect to book-entry procedures, if any;

the anti-dilution provisions of the warrants, if any;

any redemption or call provisions;

whether the warrants may be sold separately or with other securities as parts of units; and

any additional terms of the warrants, including terms, procedures and limitations relating to the exchange and exercise of the warrants.
Transfer Agent and Registrar
The transfer agent and registrar for any warrants will be set forth in the applicable prospectus supplement.
 
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DESCRIPTION OF RIGHTS
General
We may issue rights to our stockholders to purchase shares of our common stock, preferred stock or the other securities described in this prospectus. We may offer rights separately or together with one or more additional rights, debt securities, preferred stock, common stock or warrants, or any combination of those securities in the form of units, as described in the applicable prospectus supplement. Each series of rights will be issued under a separate rights agreement to be entered into between us and a bank or trust company, as rights agent. The rights agent will act solely as our agent in connection with the certificates relating to the rights of the series of certificates and will not assume any obligation or relationship of agency or trust for or with any holders of rights certificates or beneficial owners of rights. The following description sets forth certain general terms and provisions of the rights to which any prospectus supplement may relate. The particular terms of the rights to which any prospectus supplement may relate and the extent, if any, to which the general provisions may apply to the rights so offered will be described in the applicable prospectus supplement. To the extent that any particular terms of the rights, rights agreement or rights certificates described in a prospectus supplement differ from any of the terms described below, then the terms described below will be deemed to have been superseded by that prospectus supplement. We encourage you to read the applicable rights agreement and rights certificate for additional information before you decide whether to purchase any of our rights. We will provide in a prospectus supplement the following terms of the rights being issued:

the date of determining the stockholders entitled to the rights distribution;

the aggregate number of shares of common stock, preferred stock or other securities purchasable upon exercise of the rights;

the exercise price;

the aggregate number of rights issued;

whether the rights are transferrable and the date, if any, on and after which the rights may be separately transferred;

the date on which the right to exercise the rights will commence, and the date on which the right to exercise the rights will expire;

the method by which holders of rights will be entitled to exercise;

the conditions to the completion of the offering, if any;

the withdrawal, termination and cancellation rights, if any;

whether there are any backstop or standby purchaser or purchasers and the terms of their commitment, if any;

whether stockholders are entitled to oversubscription rights, if any;

any applicable material U.S. federal income tax considerations; and

any other terms of the rights, including terms, procedures and limitations relating to the distribution, exchange and exercise of the rights, as applicable.
Each right will entitle the holder of rights to purchase for cash the principal amount of shares of common stock, preferred stock or other securities at the exercise price provided in the applicable prospectus supplement. Rights may be exercised at any time up to the close of business on the expiration date for the rights provided in the applicable prospectus supplement.
Holders may exercise rights as described in the applicable prospectus supplement. Upon receipt of payment and the rights certificate properly completed and duly executed at the corporate trust office of the rights agent or any other office indicated in the prospectus supplement, we will, as soon as practicable, forward the shares of common stock, preferred stock or other securities, as applicable, purchasable upon exercise of the rights. If less than all of the rights issued in any rights offering are exercised, we may offer any
 
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unsubscribed securities directly to persons other than stockholders, to or through agents, underwriters or dealers or through a combination of such methods, including pursuant to standby arrangements, as described in the applicable prospectus supplement.
Rights Agent
The rights agent for any rights we offer will be set forth in the applicable prospectus supplement.
 
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DESCRIPTION OF UNITS
The following description, together with the additional information that we include in any applicable prospectus supplements summarizes the material terms and provisions of the units that we may offer under this prospectus. While the terms we have summarized below will apply generally to any units that we may offer under this prospectus, we will describe the particular terms of any series of units in more detail in the applicable prospectus supplement. The terms of any units offered under a prospectus supplement may differ from the terms described below.
We will incorporate by reference from reports that we file with the SEC, the form of unit agreement that describes the terms of the series of units we are offering, and any supplemental agreements, before the issuance of the related series of units. The following summaries of material terms and provisions of the units are subject to, and qualified in their entirety by reference to, all the provisions of the unit agreement and any supplemental agreements applicable to a particular series of units. We urge you to read the applicable prospectus supplements related to the particular series of units that we may offer under this prospectus, as well as any related free writing prospectuses and the complete unit agreement and any supplemental agreements that contain the terms of the units.
General
We may issue units consisting of common stock, preferred stock, one or more debt securities, warrants or rights for the purchase of common stock, preferred stock and/or debt securities in one or more series, in any combination. Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each security included in the unit. The unit agreement under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately, at any time or at any time before a specified date.
We will describe in the applicable prospectus supplement the terms of the series of units being offered, including:

the designation and terms of the units and of the securities comprising the units, including whether and under what circumstances those securities may be held or transferred separately;

any provisions of the governing unit agreement that differ from those described below; and

any provisions for the issuance, payment, settlement, transfer or exchange of the units or of the securities comprising the units.
The provisions described in this section, as well as those set forth in any prospectus supplement or as described under “Description of Common Stock,” “Description of Preferred Stock,” “Description of Debt Securities,” “Description of Warrants” and “Description of Rights” will apply to each unit, as applicable, and to any common stock, preferred stock, debt security, warrant or right included in each unit, as applicable.
Unit Agent
The name and address of the unit agent, if any, for any units we offer will be set forth in the applicable prospectus supplement.
Issuance in Series
We may issue units in such amounts and in such numerous distinct series as we determine.
Enforceability of Rights by Holders of Units
Each unit agent will act solely as our agent under the applicable unit agreement and will not assume any obligation or relationship of agency or trust with any holder of any unit. A single bank or trust company may act as unit agent for more than one series of units. A unit agent will have no duty or responsibility in case of any default by us under the applicable unit agreement or unit, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a unit may, without the consent of the related unit agent or the holder of any other unit, enforce by appropriate legal action its rights as holder under any security included in the unit.
 
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CERTAIN PROVISIONS OF DELAWARE LAW AND OF THE COMPANY’S CERTIFICATE OF INCORPORATION AND BYLAWS
Anti-Takeover Provisions
Delaware Law
We are subject to Section 203 of the Delaware General Corporation Law. Subject to certain exceptions, Section 203 prevents a publicly held Delaware corporation from engaging in a “business combination” with any “interested stockholder” for three years following the date that the person became an interested stockholder, unless the interested stockholder attained such status with the approval of our Board of Directors or unless the business combination is approved in a prescribed manner. A “business combination” includes, among other things, a merger or consolidation involving us and the “interested stockholder” and the sale of more than 10% of our assets. In general, an “interested stockholder” is any entity or person beneficially owning 15% or more of our outstanding voting stock and any entity or person affiliated with or controlling or controlled by such entity or person.
Charter Documents
Our restated certificate of incorporation and restated bylaws divide our Board of Directors into three classes with staggered three year terms. The provision for a classified board could prevent a party who acquires control of a majority of our outstanding voting stock from obtaining control of our Board of Directors until the second annual stockholders meeting following the date the acquirer obtains the controlling stock interest. Our classified board provision could discourage a potential acquirer from making a tender offer or otherwise attempting to obtain control of Quanterix and could increase the likelihood that incumbent directors will retain their positions. Our restated certificate of incorporation provides that, subject to the special rights of holders of one or more series of preferred stock, directors may be removed at any time, but only for cause by the affirmative vote of the holders of at least seventy-five percent (75%) of the voting power of all outstanding voting stock.
Our restated certificate of incorporation provides that certain amendments of our certificate of incorporation and amendments by stockholders of our restated bylaws require the approval of at least seventy-five percent (75%) of the voting power of all outstanding voting stock. These provisions could discourage a potential acquirer from making a tender offer or otherwise attempting to obtain control of Quanterix and could delay changes in management.
Our restated bylaws establish an advance notice procedure for stockholder proposals to be brought before an annual meeting of stockholders, including proposed nominations of persons for election to our Board of Directors. At an annual meeting, stockholders may only consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the direction of our Board of Directors. Stockholders may also consider a proposal or nomination by a person who was a stockholder at the time of giving notice and at the time of the meeting, who is entitled to vote at the meeting and who has complied with the notice requirements of our restated bylaws in all respects provided that such proposal is properly made in accordance with Rule 14a-8 under the Exchange Act. The restated bylaws do not give our Board of Directors the power to approve or disapprove stockholder nominations of candidates or proposals regarding other business to be conducted at a special or annual meeting of the stockholders. However, our restated bylaws may have the effect of precluding the conduct of business at a meeting if the proper procedures are not followed. These provisions may also discourage or deter a potential acquirer from conducting a solicitation of proxies to elect the potential acquirer’s own slate of directors or otherwise attempting to obtain control of Quanterix.
Our restated bylaws provide that a special meeting of stockholders may be called at any time by our Board of Directors. Because our stockholders do not have the right to call a special meeting, a stockholder cannot force stockholder consideration of a proposal over the opposition of our Board of Directors by calling a special meeting of stockholders prior to such time as a majority of the Board of Directors believed the matter should be considered. The restriction on the ability of our stockholders to call a special meeting means that a proposal to replace one or more directors on our Board of Directors also could be delayed until the next annual meeting.
 
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Our restated bylaws do not allow stockholders to act by written consent without a meeting.
Limitation of Liability and Indemnification
Our restated certificate of incorporation contains provisions that limit the liability of our directors for monetary damages to the fullest extent permitted by Delaware law. Consequently, our directors will not be personally liable to Quanterix or our stockholders for monetary damages for any breach of fiduciary duties as directors, except liability for:

any breach of the director’s duty of loyalty to Quanterix or our stockholders;

any act or omission not in good faith or that involves intentional misconduct or a knowing violation of law;

unlawful payments of dividends or unlawful stock repurchases or redemptions as provided in Section 174 or successor provisions of the Delaware General Corporation Law; or

any transaction from which the director derived an improper personal benefit.
Our restated certificate of incorporation and restated bylaws provide that Quanterix is required to indemnify its directors and officers, in each case to the fullest extent permitted by Delaware law. The restated bylaws also provide that Quanterix is obligated to advance expenses incurred by a director or officer in advance of the final disposition of any action or proceeding, subject to requirements under Delaware law, and permit us to secure insurance on behalf of any officer, director, employee or other agent for any liability arising out of his or her actions in that capacity regardless of whether we would otherwise be permitted to indemnify him or her under Delaware law.
We have entered into and expect to continue to enter into agreements to indemnify our directors, executive officers and other employees. With specified exceptions, these agreements provide for indemnification for related expenses including, among other things, attorneys’ fees, judgments, fines and settlement amounts incurred by any of these individuals in any action or proceeding brought against them by reason of the fact that they are or were Quanterix’s agents. We believe that these provisions in our restated certificate of incorporation and restated bylaws and indemnification agreements are necessary to attract and retain qualified directors and officers. We also maintain directors’ and officers’ liability insurance. This description of the limitation of liability and indemnification provisions of our restated certificate of incorporation, restated bylaws and indemnification agreements is qualified in its entirety by reference to these documents.
Insofar as indemnification for liabilities arising under the Securities Act may be permitted to our directors, officers and controlling persons pursuant to the foregoing provisions, or otherwise, we have been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable.
 
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LEGAL MATTERS
Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., Boston, Massachusetts, will pass upon the validity of the issuance of the securities to be offered by this prospectus.
EXPERTS
The Consolidated financial statements of Quanterix Corporation appearing in Quanterix Corporation’s Annual Report (Form 10-K) for the year ended December 31, 2019, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their report thereon included therein, and incorporated herein by reference. Such financial statements are, and audited financial statements to be included in subsequently filed documents will be, incorporated herein in reliance upon the reports of Ernst & Young LLP pertaining to such financial statements (to the extent covered by consents filed with the Securities and Exchange Commission) given on the authority of such firm as experts in accounting and auditing.
WHERE YOU CAN FIND MORE INFORMATION
We are subject to the reporting requirements of the Securities Exchange Act of 1934, as amended, and file annual, quarterly and current reports, proxy statements and other information with the SEC. SEC filings are available at the SEC’s web site at http://www.sec.gov. This prospectus is only part of a registration statement on Form S-3 that we have filed with the SEC under the Securities Act of 1933, as amended, and therefore omits certain information contained in the registration statement. We have also filed exhibits and schedules with the registration statement that are excluded from this prospectus, and you should refer to the applicable exhibit or schedule for a complete description of any statement referring to any contract or other document.
We also maintain a website at www.quanterix.com, through which you can access our SEC filings. The information set forth on our website is not part of this prospectus.
 
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INCORPORATION OF DOCUMENTS BY REFERENCE
The SEC allows us to “incorporate by reference” information that we file with them. Incorporation by reference allows us to disclose important information to you by referring you to those other documents. The information incorporated by reference is an important part of this prospectus, and information that we file later with the SEC will automatically update and supersede this information. We filed a registration statement on Form S-3 under the Securities Act of 1933, as amended, with the SEC with respect to the securities we may offer pursuant to this prospectus. This prospectus omits certain information contained in the registration statement, as permitted by the SEC. You should refer to the registration statement, including the exhibits, for further information about us and the securities we may offer pursuant to this prospectus. Statements in this prospectus regarding the provisions of certain documents filed with, or incorporated by reference in, the registration statement are not necessarily complete and each statement is qualified in all respects by that reference. Copies of all or any part of the registration statement, including the documents incorporated by reference or the exhibits, may be obtained upon payment of the prescribed rates at the offices of the SEC listed above in “Where You Can Find More Information.” The documents we are incorporating by reference are:

our Annual Report on Form 10-K for the fiscal year ended December 31, 2019 that we filed with the SEC on March 13, 2020;

the portions of our definitive proxy statement on Schedule 14A that we filed with the SEC on April 29, 2020 that are deemed “filed” with the SEC under the Exchange Act;

our Quarterly Report on Form 10-Q for the fiscal quarter ended March 31, 2020 that we filed with the SEC on May 7, 2020, our Quarterly Report on Form 10-Q for the fiscal quarter ended June 30, 2020 that we filed with the SEC on August 5, 2020 and our Quarterly Report on Form 10-Q for the fiscal quarter ended September 30, 2020 that we filed with the SEC on November 6, 2020;

our Current Reports on Form 8-K that we filed with the SEC on June 26, 2020, August 4, 2020, August 6, 2020, August 7, 2020, August 11, 2020, August 18, 2020 and October 5, 2020; (in each case, except for information contained therein which is furnished rather than filed);

the description of our common stock contained in our Registration Statement on Form 8-A that we filed with the SEC on December 6, 2017, including any amendment or report filed for the purpose of updating such description; and

all reports and other documents subsequently filed by us pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act after the date of this prospectus and prior to the termination or completion of the offering of securities under this prospectus shall be deemed to be incorporated by reference in this prospectus and to be a part hereof from the date of filing such reports and other documents.
The SEC file number for each of the documents listed above is 001-38319.
Any statement contained in this prospectus or in a document incorporated or deemed to be incorporated by reference into this prospectus will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or any other subsequently filed document that is deemed to be incorporated by reference into this prospectus modifies or supersedes the statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus.
You may request, orally or in writing, a copy of any or all of the documents incorporated herein by reference. These documents will be provided to you at no cost, by contacting:
Quanterix Corporation
900 Middlesex Turnpike
Billerica, MA 01821
Attention: Investor Relations
Telephone: (617) 301-9400
You may also access these documents on our website, http://www.quanterix.com. The information contained on, or that can be accessed through, our website is not a part of this prospectus. We have included our website address in this prospectus solely as an inactive textual reference.
You should rely only on information contained in, or incorporated by reference into, this prospectus and any prospectus supplement. We have not authorized anyone to provide you with information different from that contained in this prospectus or incorporated by reference in this prospectus. We are not making offers to sell the securities in any jurisdiction in which such an offer or solicitation is not authorized or in which the person making such offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make such offer or solicitation.
 
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TABLE OF CONTENTS
$200,000,000
[MISSING IMAGE: lg_quantlexington-4c.jpg]
Common Stock
Prospectus Supplement
Joint Bookrunning Managers
Goldman Sachs & Co. LLC
SVB Leerink
Cowen
Lead Manager
Canaccord Genuity
February   , 2021