X0609 4 2026-09-02-05:00 false 0001921865 ASP Isotopes Inc. ASPI 0002079961 Ainscow Donald George false C/O ASP ISOTOPES INC. 2200 ROSS AVENUE, SUITE 4575E DALLAS TX 75201 false true false false EVP, Gen Counsel, Secretary false Common Stock 2026-09-02-05:00 4 S false 23678 3.89 D 776322 D Represents shares automatically sold by ASP Isotopes Inc. (the "Company") on behalf of the reporting person pursuant to a mandatory sell-to-cover provision in the award agreement required to cover minimum statutory tax withholding obligations. The sale does not represent a discretionary trade by the reporting person. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.885 to $3.9202, inclusive. The reporting person undertakes to provide 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 this footnote. /s/ Donald Ainscow 2026-09-04