ASPI Interim CEO & COO sell-to-cover 67,500 shares at $7.51 avg

Rhea-AI Filing Summary

ASP Isotopes Inc. insider activity: The Interim CEO and COO reported selling 67,500 shares of common stock of ASP Isotopes Inc. on 11/17/2025 at a weighted average price of $7.507 per share. After this transaction, the executive beneficially owns 1,579,693 shares.

The filing explains that the sale was a "sell to cover" transaction made under a Rule 10b5-1 trading plan adopted on June 9, 2025, to cover tax withholding obligations tied to the vesting of restricted stock awards. The shares were sold in multiple trades at prices ranging from $7.215 to $7.85.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a 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). See Instruction 10.

1. Name and Address of Reporting Person^*

Ainscow Robert

(Last) (First) (Middle)

C/O ASP ISOTOPES INC.

601 PENNSYLVANIA AVENUE NW SUITE 900

(Street)

WASHINGTON DC DC 20004

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
ASP Isotopes Inc. [ ASPI ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Interim CEO and COO

3. Date of Earliest Transaction (Month/Day/Year)
11/17/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	11/17/2025		S(1)		67,500	D	$7.507(2)	1,579,693	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. 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.

2. 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.

Remarks:

	/s/ Donald Ainscow, as attorney-in-fact	11/19/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did ASP Isotopes (ASPI) report in this Form 4?

The Interim CEO and COO of ASP Isotopes Inc. (ASPI) reported selling 67,500 shares of common stock on 11/17/2025 in an open market transaction.

At what price were the ASP Isotopes (ASPI) shares sold by the insider?

The sale was reported at a weighted average price of $7.507 per share, with individual trades executed between $7.215 and $7.85 per share.

How many ASP Isotopes (ASPI) shares does the insider own after the sale?

Following the reported transaction, the Interim CEO and COO beneficially owns 1,579,693 shares of ASP Isotopes Inc. common stock.

Why did the ASP Isotopes (ASPI) insider sell 67,500 shares?

The filing states the sale represents a "sell to cover" transaction made to cover tax withholding obligations related to the vesting of restricted stock awards.

Was the ASP Isotopes (ASPI) insider sale under a Rule 10b5-1 trading plan?

Yes. The sales were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 9, 2025.

What is the insider’s role at ASP Isotopes Inc. (ASPI)?

The reporting person is identified as an Officer, serving as Interim CEO and COO of ASP Isotopes Inc.