William P. Donnelly - 01 Oct 2025 Form 4 Insider Report for Quanterix Corp (QTRX)

Role: Director
Signature: /s/ Brian Keane, as Attorney-in-Fact
Issuer symbol: QTRX
Transactions as of: 01 Oct 2025
Net transactions value: +$28,121
Form type: 4
Filing time: 03 Oct 2025, 20:54:13 UTC
Previous filing: 30 Sep 2025
Next filing: 24 Nov 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
DONNELLY WILLIAM P	Director	C/O QUANTERIX CORPORATION, 900 MIDDLESEX TURNPIKE, BILLERICA	/s/ Brian Keane, as Attorney-in-Fact	01 Oct 2025	0001207928

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	QTRX	Common Stock	Award	$28,121	+5,076	+3.5%	$5.54	148,374	01 Oct 2025	Direct	F1, F2, F3

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

Explanation of Responses:

Id	Content
F1	Consists of stock granted in lieu of cash fees for service on the Company's Board of Directors and committees thereof for the third quarter of 2025.
F2	Closing price of the Company's common stock on the Nasdaq Global Market on October 1, 2025.
F3	Includes 12,955 restricted stock units.