[Form 4] Quanterix Corporation Insider Trading Activity

Rhea-AI Filing Summary

Sriram Vandana, Chief Financial Officer and reporting person for Quanterix Corporation (QTRX), reported a change in beneficial ownership on 08/15/2025. The filing shows a disposition of 229 shares of Quanterix common stock at a price of $4.57. The filing explains those shares were withheld by Quanterix solely to cover tax obligations upon the vesting of 777 restricted stock units (RSUs). After the reported transaction, Vandana beneficially owns 83,050 shares, which the filing notes includes 72,447 restricted stock units. The form is signed by an attorney-in-fact on behalf of the reporting person on 08/19/2025.

Positive

• Timely compliance with Section 16 reporting via Form 4
• Transparency about the withholding of 229 shares to cover taxes on 777 vested RSUs
• Substantial retained stake of 83,050 shares remaining after the transaction, including 72,447 RSUs

Negative

• Minor reduction in direct beneficial ownership due to the 229-share disposition

Insights

Corporate Governance Expert

TL;DR Routine tax-withholding share disposition following RSU vesting; filing demonstrates compliance with Section 16 reporting requirements.

The reported disposition of 229 shares at $4.57 to satisfy tax obligations on 777 vested RSUs is a common, non-market-driven insider transaction. The disclosure that 72,447 RSUs remain included in beneficial ownership provides transparency about ongoing equity incentives. This filing does not indicate any unusual liquidity event or change in executive role; it documents standard post-vesting mechanics and timely reporting via Form 4.

Securities Analyst

TL;DR Small, routine share withholding to cover taxes; negligible effect on outstanding insider ownership.

The disposition reduced the reporting person\'s direct holdings by 229 shares at $4.57 per share. With 83,050 shares reported post-transaction and 72,447 RSUs included, the transaction appears administrative rather than strategic. There are no indications in the filing of additional sales, option exercises for cash, or material changes to the officer\'s equity exposure beyond standard vesting activity.

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
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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^*

Sriram Vandana

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Financial Officer

3. Date of Earliest Transaction (Month/Day/Year)
08/15/2025

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	08/15/2025		F		229(1)	D	$4.57	83,050(2)	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. Shares withheld by Quanterix Corporation solely to cover tax obligations upon the vesting of 777 RSUs.

2. Includes 72,447 restricted stock units.

Remarks:

	/s/ Brian Keane, as Attorney-in-Fact	08/19/2025
	** 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 Sriram Vandana report for QTRX?

The Form 4 reports a disposition of 229 shares of Quanterix common stock on 08/15/2025 at a price of $4.57.

Why were shares disposed of by the reporting person?

The filing states the 229 shares were withheld solely to cover tax obligations upon the vesting of 777 RSUs.

How many Quanterix shares does Vandana beneficially own after the transaction?

After the reported transaction, Vandana beneficially owns 83,050 shares, which includes 72,447 restricted stock units.

When was the Form 4 signed and by whom?

The form is signed by /s/ Brian Keane, as Attorney-in-Fact on 08/19/2025.

Does the filing indicate any other sales or exercises by the reporting person?

No. The filing only discloses the single withholding-related disposition described; no other transactions are reported.