Sec Form 4 Filing - Tang Jerry @ BlockchAIn Digital Infrastructure, Inc. - 2026-03-16

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Tang Jerry 2. Issuer Name and Ticker or Trading Symbol BlockchAIn Digital Infrastructure, Inc. [ AIB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director X __ 10% Owner X __ Officer (give title below) _____ Other (specify below) CEO and President (Last) (First) (Middle) 1540 BROADWAY, STE 1010 3. Date of Earliest Transaction (MM/DD/YY) 03/16/2026 (Street) NEW YORK, NY10036 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 03/16/2026 C 26,297,214 A 26,297,414 I See footnote ( 1 ) Common Stock 03/16/2026 D 200 D 26,297,214 I See footnote ( 1 )

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Tang Jerry 1540 BROADWAY, STE 1010 NEW YORK, NY10036 X X CEO and President Signatures /s/ Jerry Tang 03/18/2026 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Consists of shares owned by Tiger Cloud LLC ("Tiger Cloud") and VCV Digital Solutions LLC ("VCV"). Pursuant to the Business Combination Agreement, dated as of May 27, 2025, as amended, by and among Signing Day Sports, Inc., One Blockchain LLC, Issuer, parties thereto, on March 16, 2026 (the "Closing Date"), Tiger Cloud and VCV received 15,100,970 and 11,196,244 common stock of Issuer, respectively, for membership interests of One Blockchain LLC held by them, having a market value of $4.60 per share based on the last reported sale price reported by the NYSE American on the Closing Date. Tiger Cloud and VCV forfeited an aggregate of 200 shares for no consideration in connection with the closing of the business combination. Jerry Tang holds voting and investment discretion over the shares held by Tiger Cloud and VCV. Mr. Tang disclaims any beneficial ownership of the reported shares other than to the extent of any pecuniary interest he may have therein, directly or indirectly.

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).

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