Net Power Inc. President and COO Marc Horstman filed a Form 4 on November 6, 2026, disclosing a board-approved amendment to a previously granted stock option that extended the post-termination exercise period without altering other terms.

Key Highlights

  • Reporting person: Marc Horstman, President and COO of Net Power Inc. (NYSE:NPWR)
  • Transaction date: November 4, 2026, the date the board approved the amendment
  • Security affected: Stock options on 240,000 shares of Class A Common Stock
  • Exercise price unchanged: $2.13 per share, as originally granted on June 2, 2025
  • No consideration paid: According to the filing, the reporting person paid $0 for the amendment
  • Resulting ownership: 240,000 derivative securities beneficially owned directly following the reported transaction
  • Exempt transaction: The amendment is reported as a deemed cancellation and re-grant, each exempt under Rule 16b-3, according to the filing

Board Amends Horstman Option to Extend Post-Termination Exercise Window

According to the Form 4 filed with the SEC on November 6, 2026, Net Power Inc.'s board of directors on November 4, 2026 approved an amendment to a stock option originally granted to Marc Horstman on June 2, 2025. The filing states that the amendment "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.

Because SEC rules treat such modifications as a cancellation of the original award and the issuance of a new one, the filing reports both a disposition of 240,000 options (transaction code D) and an acquisition of 240,000 options (transaction code A) on the same date. The exercise price remains $2.13, the option became exercisable in full on June 2, 2026, and the expiration date remains June 2, 2030, all as stated in the filing. Horstman holds the amended options directly, with no indirect beneficial ownership reported.

The filing notes that both the deemed cancellation and the deemed re-grant are "exempt under Rule 16b-3," and that Horstman paid no consideration for the amendment. Following the reported transactions, the filing shows Horstman holds 240,000 derivative securities beneficially owned directly, with no position remaining in the original, unamended option.

What Was Disclosed

Marc Horstman, President and COO of Net Power Inc. (NYSE:NPWR), disclosed a board-approved amendment dated November 4, 2026 to his existing stock option covering 240,000 shares, extending post-termination exercise rights while leaving all other terms unchanged.