X0508 4 2026-01-19 0 0001503274 Quanterix Corp QTRX 0001564777 Cunningham Everett C/O QUANTERIX CORPORATION 900 MIDDLESEX TURNPIKE BILLERICA MA 01821 1 1 0 0 President and CEO 0 Performance-Based Restricted Stock Units 2026-01-19 4 A 0 813750 0 A 2030-01-20 Common Stock 813750 813750 D Time-Based Restricted Stock Units 2026-01-19 4 A 0 1070000 0 A 2030-01-20 Common Stock 1070000 1883750 D Each performance-based restricted stock unit ("RSU") represents a contingent right to receive one share of the Issuer's common stock. The performance-based RSUs vest upon the volume-weighted average price of the Issuer's common stock meeting certain thresholds within a four-year period, except as provided for under Section 8(y) of the Employment Agreement by and between the Issuer and the Reporting Person dated January 8, 2026. Each time-based RSU represents a contingent right to receive one share of the Issuer's common stock. The time-based RSUs vest as to one-fourth of the total number of shares on each of January 19, 2027, January 19, 2028, January 19, 2029 and January 19, 2030, except as provided for under Section 8(d) or 8(y) of the Employment Agreement by and between the Issuer and the Reporting Person dated January 8, 2026. /s/ Daniel Char, Attorney-in-Fact 2026-01-20