X0306 4 2017-12-11 0 0001503274 Quanterix Corp QTRX 0001309469 BAIN CAPITAL VENTURE INVESTORS, LLC 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001309470 BAIN CAPITAL VENTURE PARTNERS 2005, L.P. 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001309471 BAIN CAPITAL VENTURE FUND 2005, L.P. 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001379475 BCIP Associates III, LLC 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001379476 BCIP Associates III 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001379517 BCIP Associates III-B, LLC 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001379519 BCIP Associates III-B 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001212150 KRUPKA MICHAEL A C/O BAIN CAPITAL VENTURE INVESTORS, LLC 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 0001708763 Agarwal Ajay C/O BAIN CAPITAL VENTURE INVESTORS, LLC 200 CLARENDON STREET BOSTON MA 02116 0 0 1 0 Common Stock 2017-12-11 4 C 0 394273 A 394273 I See Footnotes Common Stock 2017-12-11 4 C 0 1034971 A 1429244 I See Footnotes Common Stock 2017-12-11 4 C 0 472271 A 1901515 I See Footnotes Common Stock 2017-12-11 4 C 0 108670 A 2010185 I See Footnotes Common Stock 2017-12-11 4 C 0 125900 A 2136085 I See Footnotes Series A-1 Preferred Stock 2017-12-11 4 C 0 1267200 D Common Stock 394273 0 I See Footnotes Series A-2 Preferred Stock 2017-12-11 4 C 0 3326401 D Common Stock 1034971 0 I See Footnotes Series B Preferred Stock 2017-12-11 4 C 0 1517880 D Common Stock 472271 0 I See Footnotes Series C Preferred Stock 2017-12-11 4 C 0 349271 D Common Stock 108670 0 I See Footnotes Series D Preferred Stock 2017-12-11 4 C 0 404632 D Common Stock 125900 0 I See Footnotes The shares of preferred stock automatically converted into common stock immediately prior to the closing of the Issuer's initial public offering using a calculation defined in the Issuer's Restated Certificate of Incorporation, as amended, based on the initial purchase price and the conversion rate in effect at the time of conversion. The shares of preferred stock automatically converted on a 1-for-3.214 basis and such conversion rate is reflected in the amount of common stock underlying the security. Bain Capital Venture Investors, LLC ("BCVI") is the general partner of Bain Capital Venture Partners 2005, L.P. ("BCVP"), which is the general partner of Bain Capital Venture Fund 2005, L.P. ("Fund 2005"). As a result, BCVP may be deemed to share voting and dispositive power with respect to the securities held by Fund 2005. BCVP disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 1,106,387 shares of the Issuer's Series A-1 Preferred Stock, 2,904,268 shares of the Issuer's Series A-2 Preferred Stock, 1,325,258 shares of the Issuer's Series B Preferred Stock, 304,948 shares of the Issuer's Series C Preferred Stock and 353,283 shares of the Issuer's Series D Preferred Stock held by Fund 2005 automatically converted into 344,239, 903,630, 412,339, 94,881 and 109,921 shares of the Issuer's common stock, respectively. Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 157,639 shares of the Issuer's Series A-1 Preferred Stock, 413,802 shares of the Issuer's Series A-2 Preferred Stock, 188,823 shares of the Issuer's Series B Preferred Stock, 43,449 shares of the Issuer's Series C Preferred Stock and 50,336 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III, LLC ("BCIP III"), whose manager is BCIP Associates III ("BCIPA III"), whose managing partner is Boylston Coinvestors, LLC ("Boylston"), automatically converted into 49,047, 128,749, 58,750, 13,518 and 15,663 shares of the Issuer's common stock, respectively. BCIPA III may be deemed to share voting and dispositive power with respect to the securities held by BCIP III. BCIPA III disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. Immediately prior to the closing of the Issuer's initial public offering on December 11, 2017, the 3,174 shares of the Issuer's Series A-1 Preferred Stock, 8,331 shares of the Issuer's Series A-2 Preferred Stock, 3,799 shares of the Issuer's Series B Preferred Stock, 874 shares of the Issuer's Series C Preferred Stock and 1,013 shares of the Issuer's Series D Preferred Stock held by BCIP Associates III-B, LLC ("BCIP III-B" and together with Fund 2005 and BCIP III, the "Bain Capital Entities"), whose manager is BCIP Associates III-B ("BCIPA III-B"), whose managing partner is Boylston, automatically converted into 987, 2,592, 1,182, 271 and 316 shares of the Issuer's common stock, respectively. BCIPA III-B may be deemed to share voting and dispositive power with respect to the securities held by BCIP III-B. BCIPA III-B disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein. The governance, investment strategy and decision-making process with respect to the investments held by the Bain Capital Entities is directed by the Executive Committee of BCVI, which consists of Michael A. Krupka and Ajay Agarwal. As a result, BCVI and Messrs. Krupka and Agarwal may be deemed to share voting and dispositive power with respect to the securities held by the Bain Capital Entities. BCVI and Messrs. Krupka and Agarwal disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein. These shares were convertible into the Issuer's common stock in accordance with the Issuer's Restated Certificate of Incorporation, as amended, at any time after the issuance of such shares, at the holder's election. Not applicable. Bain Capital Venture Investors, LLC, By: /s/ Michael A. Krupka, Name: Michael A. Krupka, Title: Managing Director 2017-12-11 Bain Capital Venture Partners 2005, L.P., By: Bain Capital Venture Investors, LLC, its general partner, By: /s/ Michael A. Krupka, Name: Michael A. Krupka, Title: Managing Director 2017-12-11 Bain Capital Venture Fund 2005, L.P., By: Bain Capital Venture Partners 2005, L.P., its general partner, By: Bain Capital Venture Investors, LLC, its general partner, By: /s/ Michael A. Krupka, Name: Michael A. Krupka, Title: Managing Director 2017-12-11 BCIP Associates III, LLC, By: BCIP Associates III, its manager, By: Boylston Coinvestors, LLC, its managing partner, By: /s/ Michael A. Krupka, Name: Michael A. Krupka, Title: Authorized Signatory 2017-12-11 BCIP Associates III, By: Boylston Coinvestors, LLC, its managing partner, By: /s/ Michael A. Krupka, Name: Michael A. Krupka, Title: Authorized Signatory 2017-12-11 BCIP Associates III-B, LLC, By: BCIP Associates III-B, its manager, By: Boylston Coinvestors, LLC, its managing partner, By: /s/ Michael A. Krupka, Name: Michael A. Krupka, Title: Authorized Signatory 2017-12-11 BCIP Associates III-B, By: Boylston Coinvestors, LLC, its managing partner, By: /s/ Michael A. Krupka, Name: Michael A. Krupka, Title: Authorized Signatory 2017-12-11 /s/ Michael A. Krupka 2017-12-11 /s/ Ajay Agarwal 2017-12-11