144 0002026548 XXXXXXXX LIVE 0001921865 ASP Isotopes, Inc. 001-41555 2200 Ross Avenue, Suite 4575E Dallas TX 75201 214-432-8219 Heather Kiessling Officer Common Stock J.P. Morgan Securities LLC 270 Park Avenue, 10th Floor New York NY 10017 46248 231240 125903447 04/15/2026 NASDAQ Common Stock 04/14/2026 Restricted Stock Award Issuer N 23124 04/14/2026 N/A Common Stock 04/15/2026 Restricted Stock Award Issuer N 23124 04/15/2026 N/A Y Represents sale of shares to satisfy tax withholding obligations incident to the vesting of an award of restricted stock at the rate identified by the Seller as her expected effective tax rate. Of the shares filed today, 23,124 shares are Restricted Stock that will vest within three months from the date of this filing. 04/15/2026 12/19/2025 /s/ J.P. Morgan Securities LLC as agent and attorney-in-fact for Heather Kiessling