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Table of Contents ( Mark One ) UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 10 - K ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from Delaware ( State or other jurisdiction of incorporation or organization ) 900 Middlesex Turnpike , Billerica , MA ( Address of principal executive offices ) Commission file number : 001-38319 Title of each class Common Stock , $ 0.001 par value per share QUANTERIX CORPORATION ( Exact name of registrant as specified in its charter ) Securities registered pursuant to Section 12 ( b ) of the Exchange Act : to Large accelerated filer Non - accelerated filer Trading Symbol ( s ) QTRX 20-8957988 Registrant's telephone number , including area code : ( 617 ) 301-9400 ( I.R.S. Employer Identification No. ) 01821 ( Zip Code ) Name of each exchange on which registered The Nasdaq Global Market Securities registered pursuant to Section 12 ( g ) of the Exchange Act : None Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes » No Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Exchange Act . Yes No Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes No Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S - T during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes No Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company , or an emerging growth company . See the definitions of " large accelerated filer , " " accelerated filer , " " smaller reporting company , " and " emerging growth company " in Rule 12b - 2 of the Exchange Act . Accelerated filer Smaller reporting company Emerging growth company If an emerging growth company , indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13 ( a ) of the Exchange Act . Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . Indicate by check mark hether the registrant is a shell company ( as defined Rule 12b - 2 of the Exchange Act ) . es □ No > As of the last business day of the registrant's most recently completed second fiscal quarter ( June 30 , 2020 ) , the aggregate market value of the voting and non - voting common equity held by non - affiliates of the registrant , based on the last reported sales price for the registrant's common stock , par value $ 0.001 per share , on The Nasdaq Global Market on such date , was approximately $ 234 million . As of March 1 , 2021 , the registrant had 36,267,609 shares of common stock outstanding . DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant's definitive proxy statement for its 2021 Annual Meeting of Stockholders , which the registrant intends to file with the Securities and Exchange Commission pursuant to Regulation 14A within 120 days after the end of the registrant's fiscal year ended December 31 , 2020 , are incorporated by reference into Part III of this Annual Report on Form 10 - K .