Kiessling Heather 4

What Happened

• Heather Kiessling, Chief Financial Officer of ASP Isotopes Inc. (ASPI), sold 23,124 shares on April 15, 2026. The reported weighted average price was $5.48 per share, resulting in gross proceeds of approximately $126,673. This transaction is a sale (not a purchase).

Key Details

• Transaction date: 2026-04-15 (reported on Form 4 filed 2026-04-17; filing appears timely).
• Transaction type: Sale (reported code S); listed as a "sell to cover" to satisfy tax withholding.
• Price: Weighted average $5.48; actual sale prices ranged from $5.12 to $5.71. The filer can provide a per-price breakdown on request (per filing).
• Shares disposed: 23,124.
• Shares owned after transaction: Not specified in the provided filing details.
• Footnotes: F1 – Sale effected under a Rule 10b5-1 trading plan adopted 2025-12-19 to cover tax withholding tied to vesting restricted stock. F2 – Weighted-average price note and availability of per-price breakdown.

Context

• "Sell to cover" transactions executed under a 10b5-1 plan are commonly used to pay taxes on vested awards and are generally considered routine corporate housekeeping rather than a direct signal about the insider's view of the company's prospects. The filing does not provide additional information about post-transaction holdings.