| 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 |
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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*
(Street)
(Country) | 2. Issuer Name and Ticker or Trading Symbol
ZeroStack Corp. [ ZSTK ] | 5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
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| 2a. Foreign Trading Symbol
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| 3. Date of Earliest Transaction
(Month/Day/Year) 03/31/2026 | 6. Individual or Joint/Group Filing (Check Applicable Line)
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| 4. If Amendment, Date of Original Filed
(Month/Day/Year) |
| Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned | ||||||||||
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| 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 | ||||||
| Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities) | |||||||||||||||
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| 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 | ||||||||
| Convertible Promissory Note | $33.34 | 03/31/2026 | J(1) | 4,902,220 | 10/23/2025 | 09/22/2035 | Common Shares | 4,902,220 | (2) | 0 | I | Held by Zero Gravity Labs Inc., a corporation owned and controlled by the Reporting Person | |||
| Explanation of Responses: |
| 1. On March 31, 2026, the Issuer entered into a note settlement agreement (the "Note Settlement Agreement") with Zero Gravity Labs Inc., a Delaware corporation ("0G") pursuant to which the convertible promissory note (the "Note") issued to 0G pursuant to the securities purchase agreement dated September 22, 2025, as amended on October 9, 2025, by and between the Issuer and 0G was settled. The Note Settlement Agreement provides that upon payment by the Issuer to 0G on or before March 31, 2026, of 50,000,000 Tokens (as defined in the Note), the Issuer shall be deemed to have paid the entire Principal (as defined in the Note) and Interest (as defined in the Note) of the Note in full and the Issuer shall have no further obligations under the Note and the Note shall be deemed to be satisfied. |
| 2. Represents issuance of convertible promissory note to Zero Gravity Labs Inc., a Delaware corporation owned and controlled by the Reporting Person, in the principal amount of 50,000,000 0G bitcoin tokens. |
| /s/ Dany Vaiman as attorney-in-fact for Michael Heinrich | 04/02/2026 | |
| ** 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. | ||
| * Form 4: SEC 1474 (03-26) | ||