Were Duncan Moore’s ASP Isotopes (ASPI) share sales pre-planned?

Yes. The April 16, 2026 sale was made under a Rule 10b5-1 trading plan adopted on December 31, 2025. Such plans schedule trades in advance, and this sale also included shares to satisfy income tax liabilities from restricted stock vesting.

ASP Isotopes (ASPI) director trades stock, retains over 1.04M shares

Filing Impact

(Neutral)

Filing Sentiment

(Negative)

Form Type

Rhea-AI Filing Summary

ASP Isotopes Inc. director Duncan Moore reported multiple stock transactions. He sold 11,642 shares of common stock at a weighted average price of $5.205 per share in an open-market trade. Following this sale, he directly owned 1,044,928 shares of ASP Isotopes common stock.

The filing also shows two earlier awards of restricted stock for his service as an independent director: 25,469 shares on November 12, 2025 and 36,548 shares on December 18, 2025, both granted at no cash cost. The sale on April 16, 2026 was executed under a Rule 10b5-1 trading plan adopted on December 31, 2025 and included shares sold to cover income tax liabilities from the vesting of a prior restricted stock award.

Insider Trade Summary 10b5-1

Net Seller: 11,642 shares ($60,597)

Net Sell 3 txns

Insider Moore Duncan

Role Director

Sold 11,642 shs ($61K)

Type	Security	Shares	Price	Value
Sale	Common Stock	11,642	$5.205	$61K
Grant/Award	Common Stock	36,548	$0.00	--
Grant/Award	Common Stock	25,469	$0.00	--

Holdings After Transaction: Common Stock — 1,044,928 shares (Direct)

Footnotes (1)

Award of shares of restricted stock in connection with the reporting person's service as an independent director of ASP Isotopes Inc. on the QLE Structuring and Strategic Transactions Committee. 2025 annual award of shares of restricted stock in connection with the reporting person's service as an independent director of ASP Isotopes Inc. The sale of shares reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the filing person on December 31, 2025 and includes an amount for the purpose of satisfying the reporting person's income tax liabilities resulting from the vesting of a previously granted restricted stock award pursuant to an issuer equity incentive plan. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $5.055 to $5.52, 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.

Key Figures

Shares sold: 11,642 shares Weighted average sale price: $5.205 per share Price range of sales: $5.055–$5.52 per share +3 more

6 metrics

Shares sold 11,642 shares Open-market sale on April 16, 2026

Weighted average sale price $5.205 per share April 16, 2026 common stock sale

Price range of sales $5.055–$5.52 per share Multiple transactions included in reported sale

Shares held after sale 1,044,928 shares Common stock directly owned following April 16, 2026 sale

Restricted stock award (Nov 2025) 25,469 shares Award on November 12, 2025 at $0.0000 per share

Restricted stock award (Dec 2025) 36,548 shares Award on December 18, 2025 at $0.0000 per share

Key Terms

restricted stock, Rule 10b5-1 trading plan, weighted average price, equity incentive plan

4 terms

restricted stock financial

"Award of shares of restricted stock in connection with the reporting person's service as an independent director"

Shares granted to an individual that carry limits on transfer or sale until certain conditions are met, such as staying with the company for a set time or hitting performance targets. Think of them as a locked gift that gradually opens; for investors they matter because they affect how many shares may enter the market later, signal management incentives and potential dilution, and reveal confidence in future company performance.

Rule 10b5-1 trading plan regulatory

"The sale of shares reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the filing person"

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

weighted average price financial

"The price reported in Column 4 is a weighted average price."

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

equity incentive plan financial

"previously granted restricted stock award 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.

Form 4 Insider Transactions: What Each Field Means →

04/17/2026 - 09:54 PM

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).

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^*

Moore Duncan

(Last)

(First)

(Middle)

C/O ASP ISOTOPES INC.

2200 ROSS AVENUE, SUITE 4575E

(Street)

DALLAS

TEXAS

75201

(City)

(State)

(Zip)

UNITED STATES

(Country)

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

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

X	Director	10% Owner
	Officer (give title below)	Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
11/12/2025

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

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

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

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	11/12/2025		A		25,469	A	⁽¹⁾	1,020,022	D
Common Stock	12/18/2025		A		36,548	A	⁽²⁾	1,056,570	D
Common Stock	04/16/2026		S⁽³⁾		11,642	D	$5.205⁽⁴⁾	1,044,928	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. Award of shares of restricted stock in connection with the reporting person's service as an independent director of ASP Isotopes Inc. on the QLE Structuring and Strategic Transactions Committee.

2. 2025 annual award of shares of restricted stock in connection with the reporting person's service as an independent director of ASP Isotopes Inc.

3. The sale of shares reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the filing person on December 31, 2025 and includes an amount for the purpose of satisfying the reporting person's income tax liabilities resulting from the vesting of a previously granted restricted stock award pursuant to an issuer equity incentive plan.

4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $5.055 to $5.52, 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.

	/s/ Donald Ainscow, as attorney-in-fact	04/17/2026
	** 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.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR

FAQ

What insider transactions did ASP Isotopes (ASPI) director Duncan Moore report?

Duncan Moore reported selling 11,642 ASP Isotopes common shares at a weighted average of $5.205, and previously receiving two restricted stock awards totaling 62,017 shares, granted at no cash cost as compensation for his service as an independent director.

How many ASP Isotopes (ASPI) shares does Duncan Moore hold after these transactions?

After the April 16, 2026 sale, Duncan Moore directly holds 1,044,928 shares of ASP Isotopes common stock. This figure reflects his position following the 11,642-share open-market sale executed under a pre-arranged Rule 10b5-1 trading plan.

At what price did Duncan Moore sell ASP Isotopes (ASPI) shares?

He sold 11,642 ASP Isotopes common shares at a weighted average price of $5.205 per share. The shares were executed in multiple trades between $5.055 and $5.52, with the exact breakdown available from the company or the reporting person upon request.

What restricted stock awards did Duncan Moore receive from ASP Isotopes (ASPI)?

He received 25,469 restricted shares on November 12, 2025 and 36,548 restricted shares on December 18, 2025. These awards were granted at no cash cost in connection with his service as an independent director and committee member at ASP Isotopes.

Why did Duncan Moore sell some ASP Isotopes (ASPI) shares?

The filing states the April 16, 2026 sale included shares sold to cover income tax liabilities arising from the vesting of a previously granted restricted stock award under an issuer equity incentive plan, and the trades were executed under a Rule 10b5-1 plan.