Award4

Net Power Inc.

Total Value

$1.0M

Filing Date

Nov 6, 2026

1 transactions

Trade Summary

On Nov 4, 2026, Horstman Marc, President and COO, reported $1.0M of Net Power Inc. (NPWR) across 1 transactions. The filing covers company securities and reflects balanced net activity of $0. Reported prices ranged from $2.13. Insider transactions are sourced from SEC Form 4 disclosures and should be reviewed alongside company fundamentals and the insider's broader trading history.

Insider Information

Name: Horstman Marc
Role: President and COO
Location: HOUSTON, TX

Filing Details

Filing Date: Nov 6, 2026
Transaction Date: Nov 4, 2026
Accession Number: 0001104659-26-124002
Form Type: 4

Derivative Transactions

Date	Security	Shares	Exercise Price	Type	Value
Nov 4, 2026	NPWR derivative	240,000	$2.13	Disposition	$511.2K
Nov 4, 2026	NPWR derivative	240,000	$2.13	Grant/Award	$511.2K

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Footnotes

(F1)On November 4, 2026, the Issuer's board of directors approved an amendment to the stock option granted to the reporting person on June 2, 2025, which extends the period during which the vested option may be exercised following certain terminations of service. The amendment did not change the number of shares subject to the option, its exercise price, its vesting date or its expiration date, and the reporting person paid no consideration for it. The amendment is reported as the deemed cancellation of the original option and the grant of the amended option, each of which is exempt under Rule 16b-3.
(F2)The option became exercisable in full on June 2, 2026.

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^*

Horstman Marc

(Last)

(First)

(Middle)

C/O NET POWER INC.

11700 KATY FREEWAY, SUITE 700

(Street)

HOUSTON

77079

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
Net Power Inc. [ NPWR ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
11/04/2026

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)
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)

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)
Stock Options⁽¹⁾	$2.13	11/04/2026		D			240,000	06/02/2026⁽²⁾	06/02/2030	Class A Common Stock	240,000	$0	0	D
Stock Options⁽¹⁾	$2.13	11/04/2026		A		240,000		06/02/2026⁽²⁾	06/02/2030	Class A Common Stock	240,000	$0	240,000	D

Explanation of Responses:

1. On November 4, 2026, the Issuer's board of directors approved an amendment to the stock option granted to the reporting person on June 2, 2025, which extends the period during which the vested option may be exercised following certain terminations of service. The amendment did not change the number of shares subject to the option, its exercise price, its vesting date or its expiration date, and the reporting person paid no consideration for it. The amendment is reported as the deemed cancellation of the original option and the grant of the amended option, each of which is exempt under Rule 16b-3.

2. The option became exercisable in full on June 2, 2026.

	/s/ Marc Horstman	11/06/2026
	** 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 as rendered by the SEC from accession 0001104659-26-124002.

Net Power Inc.

Trade Summary

Company Information

Insider Information

Filing Details

Derivative Transactions

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Footnotes

SEC Form 4

SEC Filing

SEC Form 4