Robert Ainscow - 17 Nov 2025 Form 4 Insider Report for ASP Isotopes Inc. (ASPI)

Role: Interim CEO and COO
Signature: /s/ Donald Ainscow, as attorney-in-fact
Issuer symbol: ASPI
Transactions as of: 17 Nov 2025
Transactions value $: -$506,723
Form type: 4
Filing time: 19 Nov 2025, 21:03:39 UTC
Previous filing: 16 Oct 2025
Next filing: 28 Nov 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Ainscow Robert	Interim CEO and COO	C/O ASP ISOTOPES INC., 601 PENNSYLVANIA AVENUE NW SUITE 900, WASHINGTON DC	/s/ Donald Ainscow, as attorney-in-fact	19 Nov 2025	0001951275

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	ASPI	Common Stock	Sale	-$507K	-67.5K	-4.1%	$7.51	1.58M	17 Nov 2025	Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id	Content
F1	Represents "sell to cover" sales effected pursuant to a Rule 10b5-1 trading plan adopted by the filing person on June 9, 2025 to cover tax withholding obligations in connection with the vesting of restricted stock awards.
F2	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $7.215 to $7.85, 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.

Content

Represents "sell to cover" sales effected pursuant to a Rule 10b5-1 trading plan adopted by the filing person on June 9, 2025 to cover tax withholding obligations in connection with the vesting of restricted stock awards.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $7.215 to $7.85, 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.