QUANTERIX CORP

Ticker: QTRX CUSIP: 74766Q101 Class: Common Stock

GROUP ONE TRADING, L.P.'s Holding History (CIK: 0000932540)

Note: Option positions (PUT/CALL) are excluded.

Q3 2025

Shares 783 Value ($000) $4 Avg Close $5.32 Range $4.15 - $7.09

Q4 2022

Shares 277,838 Value ($000) $3,848 Avg Close $11.51 Range $8.19 - $14.55

Q3 2022

Shares 45,130 Value ($000) $497 Avg Close $12.71 Range $6.31 - $19.46

Q4 2021

Shares 84 Value ($000) $4 Avg Close $46.70 Range $35.02 - $60.92

Period	Shares	Value ($000)	Average Close	Price Range
Q3 2025	783	$4	$5.32	$4.15 - $7.09
Q4 2022	277,838	$3,848	$11.51	$8.19 - $14.55
Q3 2022	45,130	$497	$12.71	$6.31 - $19.46
Q4 2021	84	$4	$46.70	$35.02 - $60.92