Sec Form 4 Filing - Garcha Jaisun @ Nano Nuclear Energy Inc. - 2026-06-03

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 Garcha Jaisun 2. Issuer Name and Ticker or Trading Symbol Nano Nuclear Energy Inc. [ NNE] 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) 10 TIMES SQUARE, 30TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 06/03/2026 (Street) NEW YORK, NY10018 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 06/03/2026 M( 1 ) 20,000 A $ 3 365,000 D Common Stock 06/03/2026 S( 3 ) 20,000 D $ 26.083 ( 4 ) 345,000 D Common Stock 06/03/2026 M( 2 ) 17,215 A $ 0 362,215 D Common Stock 06/03/2026 S( 3 ) 15,223 D $ 26.844 ( 5 ) 346,992 D Common Stock 06/03/2026 S( 3 ) 1,761 D $ 27.594 ( 6 ) 345,231 D Common Stock 06/03/2026 S( 3 ) 174 D $ 28.81 ( 7 ) 345,057 D Common Stock 06/03/2026 S( 3 ) 57 D $ 29.91 ( 8 ) 345,000 D

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 Stock Options ( 1 ) $ 3 06/03/2026 M 20,000 ( 1 ) ( 1 ) ( 1 ) Common Stock 20,000 $ 0 150,000 D Restricted Stock Units ( 2 ) $ 0 06/03/2026 M 17,215 ( 2 ) ( 2 ) ( 2 ) Common Stock 17,215 $ 0 87,845 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Garcha Jaisun 10 TIMES SQUARE, 30TH FLOOR NEW YORK, NY10018 Chief Financial Officer Signatures /s/ Jaisun Garcha 06/05/2026 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents shares of common stock issued upon exercise of certain options originally granted to the reporting person at the exercise price of $3.00 per share, which were fully vested and exercisable on June 7, 2023, with expiry on June 7, 2026. On June 3, 2026, such options were exercised. ( 2 )Represents shares of common stock issued upon the settlement of certain Restricted Stock Units ("RSUs") granted on June 3, 2025 under the Issuer's 2025 Equity Incentive Plan based on a value per share of $29.18, the closing price of the Issuer's common stock as reported on The Nasdaq Capital Market on June 3, 2025. On June 3, 2026, one third (1/3) of such RSUs were vested and settled. ( 3 )This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in September 2025. ( 4 )This transaction was executed in multiple trades during the day at prices ranging from $25.7100 to $26.4300. The weighted-average price is reported above. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected. ( 5 )This transaction was executed in multiple trades during the day at prices ranging from $26.4300 to $27.4000. The weighted-average price is reported above. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected. ( 6 )This transaction was executed in multiple trades during the day at prices ranging from $27.4300 to $27.9400. The weighted-average price is reported above. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected. ( 7 )This transaction was executed at a price of $28.8100. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected. ( 8 )This transaction was executed at a price of $29.9100. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected.

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* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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