X0609 4 2026-06-29-05:00 false 0001921865 ASP Isotopes Inc. ASPI 0001642715 Wider Todd false ASP ISOTOPES INC. 2200 ROSS AVENUE SUITE 4575E DALLAS TX 75201 true false false false false Common Stock 2026-06-29-05:00 4 S false 50000 6.25 D 722247 D Common Stock 2026-06-30-05:00 4 S false 50000 6.12 D 672247 D The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.21 to $6.31, 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 this footnote. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.10 to $6.25, 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, as attorney-in-fact 2026-07-01