Form 4 Filing for ASP Isotopes Inc.

Heather Kiessling, Chief Financial Officer of ASP Isotopes Inc., reported a disposition of 23,124 shares of common stock on July 1, 2026. The shares were sold at a weighted average price of $6.28 per share, with individual sales ranging from $6.13 to $6.52. This transaction was executed as part of a Rule 10b5-1 trading plan adopted on December 19, 2025, to cover tax withholding obligations related to restricted stock awards. Following this disposition, Ms. Kiessling owns 1,526,252 shares of common stock. The filing indicates that the sale was a "sell to cover" transaction.