ASP Isotopes holder plans sale of 1.44M shares

ASP Isotopes Inc. (ASPI) received a Form 144 notice from Paul Elliot Mann covering a planned sale of 1,441,361 shares of common stock acquired as compensation through a restricted stock award on May 28, 2026 under an issuer equity incentive plan.

Rhea-AI Filing Summary

ASP Isotopes Inc. (ASPI) received a Form 144 notice from Paul Elliot Mann covering a planned sale of 1,441,361 shares of common stock acquired as compensation through a restricted stock award on May 28, 2026 under an issuer equity incentive plan.

The planned sale’s Aggregate Market Value is stated as being based on the $3.78 closing market price on September 1, 2026. The remarks state that the sale includes shares to satisfy Mann’s income tax liabilities arising from the quarterly vesting of a 2,233,555‑share restricted stock award

Key Figures

Shares to be sold: 1,441,361 shares Reference closing market price: $3.78 per share Restricted stock award size: 2,233,555 shares +2 more

5 metrics

Shares to be sold 1,441,361 shares Common stock listed in the Securities To Be Sold section under Form 144

Reference closing market price $3.78 per share Closing market price on September 1, 2026 used to determine Aggregate Market Value

Restricted stock award size 2,233,555 shares Size of restricted stock award whose quarterly vesting triggers tax liabilities

Award grant date May 28, 2026 Date the compensation restricted stock award was acquired

Form 144 notice date September 2, 2026 Date of notice shown in the Form 144

Key Terms

Rule 144, restricted stock award, equity incentive plan, Aggregate Market Value

4 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144"

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

restricted stock award financial

"resulting from the quarterly vesting of a restricted stock award for 2,233,555 shares"

A restricted stock award is company shares given to an employee or executive that cannot be sold or fully owned until certain conditions—like staying with the company for a set time or hitting performance targets—are met. Think of it as a gift that only becomes yours after you fulfill specific obligations; for investors, these awards matter because they can increase the total shares outstanding when they vest, reveal how management is being paid and motivated, and create potential selling pressure when restrictions lift.

equity incentive plan financial

"restricted stock award for 2,233,555 shares pursuant to an issuer equity incentive plan"

An equity incentive plan is a program that gives employees, executives or directors the right to receive company stock or options to buy stock as part of their pay. Think of it as offering slices of future company profit to motivate people to boost long‑term performance; for investors it matters because it can align employee goals with shareholder value but also increases the number of shares outstanding, which can dilute existing ownership.

Aggregate Market Value financial

"The Aggregate Market Value of the shares to be sold is based on"

Aggregate market value is the combined price you would pay to buy all outstanding shares of a company or all companies in a group at current market prices — essentially the sum of each stock’s market capitalization. It matters to investors because it shows the overall size and weight of an investment or sector (like the total cost to buy every piece of a puzzle), helps compare scale across companies or markets, and influences index composition and risk exposure.

FAQ

How many ASP Isotopes Inc. (ASPI) shares are covered by this Form 144?

The notice covers a proposed sale of 1,441,361 shares of ASP Isotopes Inc. common stock, listed in the Securities To Be Sold section as common stock acquired as compensation through a restricted stock award on May 28, 2026.

At what price reference is the ASP Isotopes (ASPI) Form 144 sale valued?

The filing states that the Aggregate Market Value of the shares to be sold is based on the closing market price of $3.78 on September 1, 2026, which is used as the reference price for valuing the planned sale.

Why is Paul Elliot Mann selling ASP Isotopes (ASPI) shares under this Form 144?

The remarks state that the sale includes an amount for satisfying income tax liabilities resulting from the quarterly vesting of a restricted stock award for 2,233,555 shares granted pursuant to an issuer equity incentive plan.

How were the ASP Isotopes (ASPI) shares being sold acquired?

The Form 144 states that the common stock was acquired as compensation through a Restricted Stock Award dated May 28, 2026, under an issuer equity incentive plan, and classifies the acquisition type as Equity Compensation.

Through which broker and market may the ASP Isotopes (ASPI) Form 144 shares be sold?

The securities information lists Independent Trading Group (ITG) Inc. as the broker, with potential sales of ASP Isotopes Inc. common stock on the Nasdaq market on dates including September 2, 2026, and subsequent days.

What prior ASP Isotopes (ASPI) sales by Paul Elliot Mann are disclosed?

The filing’s three‑month sales section lists common stock sales for Paul Elliot Mann on June 2, 2026, and June 3, 2026, each associated with ASP Isotopes Inc. common stock, with line items that include numerical amounts for each date.

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Available on EDGAR 09/02/2026 - 09:31 PM Accepted by SEC EDGAR 09/02/2026 - 09:30 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001744816
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	ASP Isotopes Inc.
SEC File Number	001-41555
Address of Issuer	2200 ROSS AVENUE, SUITE 4575E, DALLAS TEXAS 75201
Phone	2144328219
Name of Person for Whose Account the Securities are To Be Sold	Mann Paul Elliot
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	DIRECTOR
Relationship to Issuer	OFFICER

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common Stock	Independent Trading Group (ITG) Inc. 33 YONGE STREET, SUITE 420, TORONTO A6 M5E 1G4	83758	316605	153309380	09/02/2026	NASDAQ
Common Stock	Independent Trading Group (ITG) Inc. 33 YONGE STREET, SUITE 420, TORONTO A6 M5E 1G4	83758	316605	153309380	09/03/2026	NASDAQ
Common Stock	Independent Trading Group (ITG) Inc. 33 YONGE STREET, SUITE 420, TORONTO A6 M5E 1G4	83759	316609	153309380	09/04/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common Stock	05/28/2026	Acquired as compensation --Restricted Stock Award	Issuer			1441361	05/28/2026	Equity Compensation

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Mann Paul Elliot 2200 ROSS AVENUE, SUITE 4575E, DALLAS TX 75201	Common Stock	06/03/2026	83759	649969.84
Mann Paul Elliot 2200 ROSS AVENUE, SUITE 4575E, DALLAS TX 75201	Common Stock	06/02/2026	83758	694353.82

144: Remarks and Signature

Remarks	The sale of shares reported in this Form 144 includes an amount for the purpose of satisfying the Reporting Person's income tax liabilities resulting from the quarterly vesting of a restricted stock award for 2,233,555 shares pursuant to an issuer equity incentive plan. The Aggregate Market Value of the shares to be sold is based on the closing market price of $3.78 on September 1, 2026.
Date of Notice	09/02/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	12/30/2025
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Paul Elliot Mann
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)