Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 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 that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * Gould Greg 2. Issuer Name and Ticker or Trading Symbol Horizon Quantum Holdings Ltd. [HQ] 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 (Last) (First) (Middle) C/O HORIZON QUANTUM HOLDINGS LTD., 29 MEDIA CIR. #05-22 3. Date of Earliest Transaction (Month/Day/Year) 06/12/2026 (Street) SINGAPORE 138565 4. If Amendment, Date 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 (City) (State) (Zip) 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 Class A Ordinary Shares 09/12/2026(1) M 3,437(1) A $ 0 (2) 3,437 D Class A Ordinary Shares 09/12/2026(1) D 1,272(3) D $15.22(3) 2,165 D

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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 Underlying Securities (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 of Derivative Security: 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

Restricted Stock Unit

$ 0 (2)

06/12/2026

A

54,995(2)

(2)

(2)

Class A Ordinary Shares

54,995(2)

$ 0

54,995

D

Restricted Stock Unit

$ 0 (2)

09/12/2026

M

3,437(1)

(1)(2)

(2)

Class A Ordinary Shares

3,437

$ 0

51,558

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Gould Greg C/O HORIZON QUANTUM HOLDINGS LTD. 29 MEDIA CIR. #05-22 SINGAPORE 138565			Chief Financial Officer

Signatures

/s/ Greg Gould		09/15/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	On September 12, 2026, 3,437 of Mr. Gould's RSU's vested.
(2)	On June 12, 2026 (the "Grant Date"), Mr. Gould was granted a total of 54,995 unvested restricted stock unites ("RSUs"), each representing a contingent right to receive one Class A ordinary share, with no par value ("Class A Ordinary Share"), of Horizon Quantum Holdings Ltd. (the "Company") upon vesting, for no consideration.. The RSUs granted to Mr. Gould vest in sixteen approximately equal installments on successive quarterly anniversaries of the Grant Date and are subject to Mr. Gould's continued employment with the Company through each applicable vesting date.
(3)	The reported disposition to the Company reflects the settlement in cash of a portion of the RSUs which vested on September 12, 2026, at a price per ordinary share of $15.22, the last reported sales price of the Company's Class A Ordinary Shares on September 11, 2026.

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