William P. Donnelly - Nov 20, 2025 Form 4 Insider Report for Quanterix Corp (QTRX)

Role: Executive Chair, Director
Signature: /s/ Bonnie McManus, as Attorney-in-Fact
Stock symbol: QTRX
Transactions as of: Nov 20, 2025
Transactions value $: $0
Form type: 4
Date filed: 11/24/2025, 07:07 PM
Previous filing: Oct 3, 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
DONNELLY WILLIAM P	Executive Chair, Director	C/O QUANTERIX CORPORATION, 900 MIDDLESEX TURNPIKE, BILLERICA	/s/ Bonnie McManus, as Attorney-in-Fact	2025-11-24	0001207928

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	QTRX	Stock Options (Right to buy)	Award	$0	+70.1K		$0.00	70.1K	Nov 20, 2025	Common Stock	70.1K	$5.91	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The stock options vest monthly over two years in 24 equal installments, subject to the Reporting Person's provision of service to the Issuer on each vesting date.