X0306 4 2020-04-01 false 0001503274 Quanterix Corp QTRX 0001219039 CRANDELL KEITH 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO IL 60631 true false true false Common Stock 2020-04-01 4 A false 611.00 19.21 A 9311.00 D Common Stock 2412001.00 I Held by ARCH Venture Fund VI, L.P. Common Stock 1537684.00 I Held by ARCH Venture Fund VIII Overage, L.P. Consists of stock granted in lieu of cash fees for service on the Company's Board of Directors and committees thereof for the first quarter of 2020, pursuant to an election made in December 2019. Closing price of the Company's common stock on the Nasdaq Global Market on April 1, 2020. Includes 2,270 restricted stock units. The shares are held of record by ARCH Venture Fund VI, L.P. ("ARCH Fund VI"). The sole general partner of ARCH Fund VI is ARCH Venture Partners VI, L.P. ("ARCH Partners VI"), which may be deemed to beneficially own the shares held by ARCH Fund VI. The sole general partner of ARCH Partners VI is ARCH Venture Partners VI, LLC ("ARCH VI LLC"), which may be deemed to beneficially own the shares held by ARCH Fund VI. ARCH Partners VI and ARCH VI LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VI LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund VI. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The shares are held of record by ARCH Venture Fund VIII Overage, L.P. ("ARCH Fund Overage"). The sole general partner of ARCH Fund Overage is ARCH Venture Partners VIII, LLC ("ARCH VIII LLC"), which may be deemed to beneficially own the shares held by ARCH Fund Overage. ARCH VIII LLC disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein. As a managing director of ARCH VIII LLC, the Reporting Person may be deemed to beneficially own the shares held by ARCH Fund Overage. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein. /s/ Brian Keane, as Attorney-in-Fact for Keith L. Crandell 2020-04-03