X0609 4 2026-04-13-05:00 false 0001921865 ASP Isotopes Inc. ASPI 0001951275 Ainscow Robert false C/O ASP ISOTOPES INC. 2200 ROSS AVENUE, SUITE 4575E DALLAS TX 75201 false true false false COO true Common Stock 2026-03-06-05:00 4 S false 25000 4.511 D 1512817 D Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the filing person on December 13, 2024. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $4.42 to $4.58, inclusive. The reporting person undertakes to provide ASP Isotopes Inc. (the "Company"), any stockholder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in Footnote 2. /s/ Donald Ainscow, as attorney-in-fact 2026-04-13