SEC FORM 4SEC Form 4
FORM 4UNITED 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
 
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1. Name and Address of Reporting Person*
Fitzsimons Joseph Francis

(Last)(First)(Middle)
C/O HORIZON QUANTUM HOLDINGS LTD.
29 MEDIA CIR. #05-22

(Street)
SINGAPORE138565

(City)(State)(Zip)
SINGAPORE

(Country)
2. Issuer Name and Ticker or Trading Symbol
Horizon Quantum Holdings Ltd. [ HQ ]
Foreign Trading Symbol
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
checkbox checkedDirectorcheckbox checked10% Owner
checkbox checkedOfficer (give title below)Other (specify below)
Chief Executive Officer
3. Date of Earliest Transaction (Month/Day/Year)
06/12/2026
4. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
checkbox checkedForm 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)
CodeVAmount(A) or (D)Price
Class A Ordinary Shares09/12/2026(1)M14,321(1)A$0(2)14,321D
Class A Ordinary Shares09/12/2026(1)D3,438(3)D$15.22(3)10,883D
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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Restricted Stock Unit$0(2)06/12/2026A229,148(2) (2) (2)Class A Ordinary Shares229,148(2)$0229,148D
Restricted Stock Unit$0(2)09/12/2026M14,321(1) (1)(2) (2)Class A Ordinary Shares14,321$0214,827D
Explanation of Responses:
1. On September 12, 2026, 14,321 of Dr. Fitzsimons's RSU's vested.
2. On June 12, 2026 (the "Grant Date"), Dr. Fitzsimons was granted a total of 229,148 unvested restricted stock units ("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 Dr. Fitzsimons vest in sixteen approximately equal installments on successive quarterly anniversaries of the Grant Date and are subject to Dr. Fitzsimons'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.
/s/ Joseph Francis Fitzsimons09/15/2026
** Signature of Reporting PersonDate
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* 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).
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