Nano Nuclear Energy (NNE)

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-06-03 10b5-1 Pre-arranged Plan: Yes --- Issuer --- Name: Nano Nuclear Energy Inc. (NNE) CIK: 0001923891 --- Reporting Owner --- Name: Walker James John CIK: 0002021757 Role: Director, Officer (Chief Executive Officer) --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock Date: 2026-06-03 | Code: M (Exercise of derivative) Shares: +70,000 | Price: $3.00 Total Value: $210,000.00 Shares Owned After: 650,000 | Ownership: D (Direct) Footnotes: [F1] 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. [Transaction #2] Security: Common Stock Date: 2026-06-03 | Code: S (Open market sale) Shares: -46,145 | Price: $26.18 Total Value: $1,208,029.96 Shares Owned After: 603,855 | Ownership: D (Direct) Footnotes: [F3] This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in September 2025. [F4] This transaction was executed in multiple trades during the day at prices ranging from $25.7100 to $26.7000. 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. [Transaction #3] Security: Common Stock Date: 2026-06-03 | Code: S (Open market sale) Shares: -22,380 | Price: $27.06 Total Value: $605,669.94 Shares Owned After: 581,475 | Ownership: D (Direct) Footnotes: [F3] This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in September 2025. [F5] This transaction was executed in multiple trades during the day at prices ranging from $26.7050 to $27.6800. 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. [Transaction #4] Security: Common Stock Date: 2026-06-03 | Code: S (Open market sale) Shares: -1,475 | Price: $27.90 Total Value: $41,152.50 Shares Owned After: 580,000 | Ownership: D (Direct) Footnotes: [F3] This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in September 2025. [F6] This transaction was executed in multiple trades during the day at prices ranging from $27.7200 to $28.3750. 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. [Transaction #5] Security: Common Stock Date: 2026-06-03 | Code: M (Exercise of derivative) Shares: +28,688 | Price: $0.00 Shares Owned After: 608,688 | Ownership: D (Direct) Footnotes: [F2] 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. [Transaction #6] Security: Common Stock Date: 2026-06-03 | Code: S (Open market sale) Shares: -25,792 | Price: $26.77 Total Value: $690,426.05 Shares Owned After: 582,896 | Ownership: D (Direct) Footnotes: [F3] This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in September 2025. [F7] This transaction was executed in multiple trades during the day at prices ranging from $26.3700 to $27.3400. 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. [Transaction #7] Security: Common Stock Date: 2026-06-03 | Code: S (Open market sale) Shares: -2,624 | Price: $27.55 Total Value: $72,304.32 Shares Owned After: 580,272 | Ownership: D (Direct) Footnotes: [F3] This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in September 2025. [F8] This transaction was executed in multiple trades during the day at prices ranging from $27.3700 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. [Transaction #8] Security: Common Stock Date: 2026-06-03 | Code: S (Open market sale) Shares: -201 | Price: $28.69 Total Value: $5,766.49 Shares Owned After: 580,071 | Ownership: D (Direct) Footnotes: [F3] This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in September 2025. [F9] This transaction was executed in multiple trades during the day at prices ranging from $28.6600 to $28.9000. 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. [Transaction #9] Security: Common Stock Date: 2026-06-03 | Code: S (Open market sale) Shares: -71 | Price: $29.91 Total Value: $2,123.61 Shares Owned After: 580,000 | Ownership: D (Direct) Footnotes: [F3] This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in September 2025. [F10] 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. [Transaction #10] Security: Common Stock Date: 2026-06-03 | Code: S (Open market sale) Shares: -25,000 | Price: $26.04 Total Value: $650,950.00 Shares Owned After: 555,000 | Ownership: D (Direct) Footnotes: [F3] This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in September 2025. [F11] This transaction was executed in multiple trades during the day at prices ranging from $25.7100 to $26.3700. 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. --- Derivative Transactions --- [Transaction #1] Security: Stock Options Date: 2026-06-03 | Code: M (Exercise of derivative) Shares: -70,000 | Price: $0.00 Shares Owned After: 430,000 | Ownership: D (Direct) Footnotes: [F1] 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. [F1] 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. [F1] 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. [Transaction #2] Security: Restricted Stock Units Date: 2026-06-03 | Code: M (Exercise of derivative) Shares: -28,688 | Price: $0.00 Shares Owned After: 146,398 | Ownership: D (Direct) Footnotes: [F2] 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. [F2] 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. [F2] 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. [F2] 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. --- Footnotes (Complete Index) --- F1: 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. F10: 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. F11: This transaction was executed in multiple trades during the day at prices ranging from $25.7100 to $26.3700. 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. F2: 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. F3: This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in September 2025. F4: This transaction was executed in multiple trades during the day at prices ranging from $25.7100 to $26.7000. 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. F5: This transaction was executed in multiple trades during the day at prices ranging from $26.7050 to $27.6800. 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. F6: This transaction was executed in multiple trades during the day at prices ranging from $27.7200 to $28.3750. 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. F7: This transaction was executed in multiple trades during the day at prices ranging from $26.3700 to $27.3400. 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. F8: This transaction was executed in multiple trades during the day at prices ranging from $27.3700 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. F9: This transaction was executed in multiple trades during the day at prices ranging from $28.6600 to $28.9000. 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. --- Signature --- /s/ /s/ James John Walker (2026-06-05)