William P. Donnelly - 17 Aug 2026 Form 4 Insider Report for Quanterix Corp (QTRX)

Reporting relationship: Director
Issuer ticker: QTRX
Reported as of: 17 Aug 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 19 Aug 2026, 06:37:50 UTC
Prior SEC filing: 14 Aug 2026
Source filing: View source filing
Reporting owner signature: /s/ Meghan Shevlin, Attorney-in-Fact

Key filing fact

William P. Donnelly filed Form 4 for Quanterix Corp (QTRX) on 19 Aug 2026.

Key facts

This page summarizes William P. Donnelly's Form 4 filing for Quanterix Corp (QTRX).
2 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 19 Aug 2026, 06:37.

Change

Previous filing in this sequence was filed on 14 Aug 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001207928 Primary reporting owner

DONNELLY WILLIAM P

Relationship: Director
Address: C/O QUANTERIX CORPORATION, 900 MIDDLESEX TURNPIKE, BILLERICA
Signature: /s/ Meghan Shevlin, Attorney-in-Fact
Signature date: 19 Aug 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

QTRX transaction

Common Stock

Options Exercise

Transaction value
Shares: +2,802
Change %: +1.8%
Price
Shares after: 162,401
Date: 17 Aug 2026
Ownership: Direct
Footnotes: F1

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

QTRX transaction Derivative

Restricted Stock Unit

Options Exercise

Transaction value
Shares: -2,802
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 17 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 2,802
Exercise price: $0.000000
Footnotes: F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

Restricted stock units convert into common stock on a one-for-one basis.

Footnote F2

On August 17, 2023, the reporting person was granted 8,238 restricted stock units, vesting 33%, 33%, and 34% on the first, second, and third anniversaries of the grant date, respectively.