X0306 4 2019-05-01 false 0001503274 Quanterix Corp QTRX 0001252546 HRUSOVSKY E KEVIN C/O QUANTERIX CORPORATION, 113 HARTWELL AVENUE LEXINGTON MA 02421 true true false false Chairman, President & CEO Common Stock 2019-05-01 4 S false 2142.00 22.5925 D 1180268.00 D The sale of shares reported on this Form 4 was made solely to cover tax obligations upon the vesting of 6,911 RSUs. This transaction was executed in multiple trades at prices ranging from $22.40 to $22.7812. The price reported reflects the weighted average sale price. The reporting person undertakes to provide upon request to the SEC staff, the issuer or any security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. Includes 39,815 shares of common stock that are subject to performance based vesting and 229,088 restricted stock units. /s/ Brian Keane, as Attorney-in-Fact 2019-05-02