144 0002079961 XXXXXXXX LIVE 0001921865 ASP Isotopes Inc. 001-41555 2200 ROSS AVENUE SUITE 4575E DALLAS TX 75201 2144328219 Ainscow Donald George OFFICER Common Stock CitiGroup Global Mkts. Inc.

153 East 53rd Street 19th Floor New York NY 10022

100000 622000.00 125903447 06/30/2026 NASDAQ Common Stock 09/29/2021 Private placement Issuer N 100000 09/29/2021 Cash Y The Aggregate Market Value of the shares to be sold is based on the closing market price of $6.22 on June 29, 2026. 06/30/2026 /s/ Donald George Ainscow