Quanterix (QTRX) Executive Chair receives 6,178-share stock grant

Rhea-AI Filing Summary

DONNELLY WILLIAM P reported acquisition or exercise transactions in this Form 4 filing.

Quanterix Corp Executive Chair William P. Donnelly received 6,178 shares of Common Stock as a stock grant. The shares were awarded at a stated price of $0.00 per share as a grant or award transaction, rather than an open-market purchase or sale.

According to the disclosure, this stock was granted in lieu of cash fees for Donnelly’s service on Quanterix’s Board of Directors and its committees for the first quarter of 2026. Following this award, Donnelly directly holds a total of 154,127 shares of Quanterix Common Stock.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider DONNELLY WILLIAM P

Role Executive Chair

Type	Security	Shares	Price	Value
Grant/Award	Common Stock	6,178	$0.00	--

Holdings After Transaction: Common Stock — 154,127 shares (Direct)

Footnotes (1)

1. [object Object]

Key Figures

Stock grant: 6,178 shares Grant price: $0.00 per share Post-transaction holdings: 154,127 shares +1 more

4 metrics

Stock grant 6,178 shares Common Stock granted on April 1, 2026

Grant price $0.00 per share Stated transaction price for the stock grant

Post-transaction holdings 154,127 shares Direct Common Stock holdings after the grant

Compensation period First quarter of 2026 Board and committee fees paid in stock

Key Terms

Grant, award, or other acquisition, Common Stock, stock granted in lieu of cash fees, Board of Directors

4 terms

Grant, award, or other acquisition financial

"transaction_code_description: "Grant, award, or other acquisition""

Common Stock financial

"security_title: "Common Stock""

Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.

stock granted in lieu of cash fees financial

"Consists of stock granted in lieu of cash fees for service"

Board of Directors financial

"service on the Company's Board of Directors and committees thereof"

The Board of Directors is a group of people chosen by a company's owners to help make big decisions and oversee how the company is run. They act like a team of advisors or managers, making sure the company stays on track and meets its goals. Their choices can influence the company's success and how it grows.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

DONNELLY WILLIAM P

(Last) (First) (Middle)

C/O QUANTERIX CORPORATION

900 MIDDLESEX TURNPIKE

(Street)

BILLERICA MASSACHUSETTS 01821

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Quanterix Corp [ QTRX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Executive Chair

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/01/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	04/01/2026		A		6,178(1)	A	$0.00	154,127	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Consists of stock granted in lieu of cash fees for service on the Company's Board of Directors and committees thereof for the first quarter of 2026.

Remarks:

	/s/ Bonnie McManus, as Attorney-in-Fact	04/03/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did Quanterix (QTRX) report for William P. Donnelly?

Quanterix reported that Executive Chair William P. Donnelly received 6,178 shares of Common Stock as a stock grant. The award was categorized as a grant, award, or other acquisition and was not an open-market buy or sell transaction.

Why did William P. Donnelly receive 6,178 Quanterix (QTRX) shares?

Donnelly received 6,178 Quanterix shares as stock granted in lieu of cash fees. The footnote states this covered his compensation for service on the company’s Board of Directors and its committees for the first quarter of 2026.

What was the price per share for William P. Donnelly’s Quanterix stock grant?

The Form 4 lists the transaction price per share as $0.00 for Donnelly’s 6,178-share grant. This reflects that the shares were granted as compensation, rather than purchased for cash in an open-market transaction.

How many Quanterix (QTRX) shares does William P. Donnelly hold after this grant?

After receiving the 6,178-share grant, Donnelly directly holds 154,127 shares of Quanterix Common Stock. This total includes the newly granted shares and represents his reported direct ownership following the transaction on April 1, 2026.

What role does William P. Donnelly hold at Quanterix (QTRX)?

William P. Donnelly is identified as Executive Chair and a director at Quanterix. The shares granted to him relate to his service on the company’s Board of Directors and its committees during the first quarter of 2026, according to the filing footnote.