[SCHEDULE 13D/A] Quanterix Corporation SEC Filing

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 2)

Quanterix Corp

(Name of Issuer)

Common Stock, $0.001 par value per share

(Title of Class of Securities)

74766Q101

(CUSIP Number)

BENJAMIN NATTER
KENT LAKE PR LLC, Carr. 115 km 12.1 Ave., Albizu Campos #2490 Suite 28
Rincon, PR, 00677
415-237-0007

SEBASTIAN ALSHEIMER, ESQ.
WILSON SONSINI GOODRICH & ROSATI, 1301 Avenue of the Americas
New York, NY, 10019
(212) 999-5800

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

07/11/2025

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No. 74766Q101

1

Name of reporting person

Kent Lake Partners LP

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 2,089,500.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 2,089,500.00

11

Aggregate amount beneficially owned by each reporting person

2,089,500.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

4.5 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP No. 74766Q101

1

Name of reporting person

Kent Lake PR LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

PUERTO RICO

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 2,089,500.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 2,089,500.00

11

Aggregate amount beneficially owned by each reporting person

2,089,500.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

4.5 %

14

Type of Reporting Person (See Instructions)

IA, HC

SCHEDULE 13D

CUSIP No. 74766Q101

1

Name of reporting person

Benjamin Natter

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 2,089,500.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 2,089,500.00

11

Aggregate amount beneficially owned by each reporting person

2,089,500.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

4.5 %

14

Type of Reporting Person (See Instructions)

IN, HC

SCHEDULE 13D

CUSIP No. 74766Q101

1

Name of reporting person

Alexander G. Dickinson

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

0.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

CUSIP No. 74766Q101

1

Name of reporting person

Bruce Felt

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

0.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

CUSIP No. 74766Q101

1

Name of reporting person

Hakan Sakul

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

0.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, $0.001 par value per share
(b)	Name of Issuer: Quanterix Corp
(c)	Address of Issuer's Principal Executive Offices: 900 MIDDLESEX TURNPIKE, BILLERICA, MASSACHUSETTS , 01821.
Item 1 Comment: Comment: The following constitutes Amendment No. 2 to the Schedule 13D filed by the undersigned ("Amendment No. 2"). This Amendment No. 2 amends the Schedule 13D as specifically set forth herein. Unless otherwise defined herein, all capitalized terms used herein shall have the meanings given to them in the Schedule 13D.
Item 3.	Source and Amount of Funds or Other Consideration
	Item 3 is hereby amended and restated to read as follows: The securities purchased by Kent Lake Partners, were purchased with working capital in open market purchases as set forth in Exhibit 1, which is incorporated by reference herein. The aggregate purchase price of the 2,089,500 Shares directly owned by Kent Lake Partners is approximately $16,846,942, including brokerage commissions.
Item 4.	Purpose of Transaction
	Item 4 is hereby amended to add the following: As previously disclosed in Amendment No. 1 to the Schedule 13D, on February 28, 2025, Kent Lake delivered a letter to the Issuer nominating Alexander G. Dickinson, Bruce Felt and Hakan Sakul (the "Nominees") for election to the Board of Directors of the Issuer (the "Board") at the 2025 annual meeting of stockholders (the "Annual Meeting"). On July 11, 2025, Kent Lake resubmitted its nomination of the Nominees for election to the Board at the Annual Meeting following the Issuer's disclosure that the Annual Meeting will now be held on September 23, 2025.
Item 5.	Interest in Securities of the Issuer
(a)	Items 5(a)-(c) are hereby amended and restated to read as follows: As of the date hereof, the Reporting Persons beneficially own 2,089,500 shares in the aggregate, representing approximately 4.5% of the outstanding Shares. The aggregate percentage of Shares reported owned by the Reporting Persons herein is based upon approximately 46,654,879 outstanding, which is the total number of shares outstanding as reported in the Issuer's Post-Effective Amendment No. 3 on Form S-8 filed with the Securities and Exchange Commission on July 11, 2025.
(b)	The Reporting Persons have sole voting power and sole investment power with respect to the Shares beneficially owned by the Reporting Persons.
(c)	During the past sixty days, none of the Reporting Persons has effected any transaction in the Shares, except as set forth in Exhibit 1, which is incorporated herein by reference.
(d)	No person other than the Reporting Persons is known to have the right to receive, or the power to direct the receipt of dividends from, or proceeds from the sale of, the Shares.
(e)	As of July 11, 2025, the Reporting Persons ceased to beneficially own more than 5% of the outstanding Shares of the Issuer.
Item 7.	Material to be Filed as Exhibits.
	Item 7 is hereby amended to add the following exhibits: Exhibit 1: Transactions in the Shares.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Kent Lake Partners LP

Signature:	/s/ Benjamin Natter
Name/Title:	Managing Member
Date:	07/15/2025

Kent Lake PR LLC

Signature:	/s/ Benjamin Natter
Name/Title:	Managing Member
Date:	07/15/2025

Benjamin Natter

Signature:	/s/ Benjamin Natter
Name/Title:	Indvidually and as attorney-in-fact for Alexander G. Dickinson, Bruce Felt and Hakan Sakul
Date:	07/15/2025

Alexander G. Dickinson

Signature:	/s/ Benjamin Natter
Name/Title:	Indvidually and as attorney-in-fact for Alexander G. Dickinson, Bruce Felt and Hakan Sakul
Date:	07/15/2025

Bruce Felt

Signature:	/s/ Benjamin Natter
Name/Title:	Indvidually and as attorney-in-fact for Alexander G. Dickinson, Bruce Felt and Hakan Sakul
Date:	07/15/2025

Hakan Sakul

Signature:	/s/ Benjamin Natter
Name/Title:	Indvidually and as attorney-in-fact for Alexander G. Dickinson, Bruce Felt and Hakan Sakul
Date:	07/15/2025