144 0001951275 XXXXXXXX LIVE 0001921865 ASP Isotopes Inc. 001-41555 2200 Ross Avenue Suite 4575E Dallas TX 75201 (214) 4328219 Ainscow Robert OFFICER Common Stock Independent Trading Group (ITG) Inc.

33 Yonge Street Suite 420 Toronto A6 M5E 1G4

22500 121050.00 125903447 04/16/2026 NASDAQ Common Stock 04/14/2025 Acquired as compensation --Restricted Stock Award Issuer N 400000 04/14/2025 Equity Compensation N Ainscow Robert

c/o ASP Isotopes Inc. 2200 Ross Avenue, Suite 4575E Dallas TX 75201

Common Stock 03/06/2026 8438 45894.28 Ainscow Robert

c/o ASP Isotopes Inc. 2200 Ross Avenue, Suite 4575E Dallas TX 75201

Common Stock 04/13/2026 25000 112775.00 The sale of shares reported in this Form 144 is expected to be sold on the date indicated pursuant to a Rule 10b5-1 trading plan and includes an amount for the purpose of satisfying the Reporting Person's income tax liabilities resulting from the quarterly vesting of a previously granted restricted stock award for 400,000 shares pursuant to an issuer equity incentive plan. The Aggregate Market Value of the shares to be sold is based on the closing market price of $5.38 on April 15, 2026. 04/16/2026 06/09/2025 /s/ Robert Ainscow