[Form 4] Quanterix Corp Insider Trading Activity

Rhea-AI Filing Summary

Quanterix Corp (QTRX)November 20, 2025, the director acquired 46,727 shares of common stock through a grant of restricted stock units (RSUs), reported as an acquisition in a Form 4 filing. Following this grant, the director beneficially owns 46,727 shares directly.

The RSUs vest in three equal installments. One-third of the total shares vest on each of November 20, 2026, November 20, 2027 and November 20, 2028, provided the director continues to provide service to Quanterix on each vesting date. This filing reflects routine director equity compensation rather than an open‑market purchase or sale.

11/25/2025 - 02:37 PM

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

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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^*

Hampton Malcolm Garret

(Last) (First) (Middle)

C/O QUANTERIX CORPORATION

900 MIDDLESEX TURNPIKE

(Street)

BILLERICA MA 01821

(City) (State) (Zip)

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
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
11/20/2025

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

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

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

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	11/20/2025		A		46,727	A	(1)	46,727	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. Represents the number of shares of common stock issuable on the vesting of restricted stock units ("RSUs"). The RSUs vest as to one-third of the total number of shares on each of November 20, 2026, November 20, 2027 and November 20, 2028, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

Remarks:

	/s/ Bonnie McManus, Attorney-in-Fact	11/24/2025
	** 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.

FAQ

What transaction did Quanterix Corp (QTRX) disclose in this Form 4?

The filing reports that a director of Quanterix Corp (QTRX) acquired 46,727 shares of common stock via a grant of restricted stock units (RSUs) on November 20, 2025.

How many Quanterix (QTRX) shares are covered by the new RSU grant?

The RSU grant covers 46,727 shares of Quanterix common stock, which are reflected as beneficially owned by the director following the reported transaction.

How do the Quanterix (QTRX) RSUs vest for this director award?

The RSUs vest as to one-third of the total 46,727 shares on each of November 20, 2026, November 20, 2027 and November 20, 2028, subject to continued service.

Is the Quanterix (QTRX) Form 4 transaction a purchase or a stock sale?

The Form 4 reports an acquisition of 46,727 shares through a restricted stock unit grant, not an open‑market stock purchase or sale.

What is the reporting person’s relationship to Quanterix Corp (QTRX)?

The reporting person is a director of Quanterix Corp, as indicated in the relationship section of the Form 4.

Does the Quanterix (QTRX) Form 4 indicate joint filing by multiple insiders?

No. The document states that the Form is filed by one reporting person, not by more than one reporting person.