Asa Akastor - 02 Apr 2026 Form 4 Insider Report for HMH Holding Inc (HMH)

Reporting relationship: 10%+ Owner
Issuer ticker: HMH
Reported as of: 02 Apr 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 02 Apr 2026, 16:19:49 UTC
Prior SEC filing: 31 Mar 2026
Next SEC filing: 04 May 2026
Source filing: View source filing
Reporting owner signature: /s/ Karl Erik Kjelstad, as Chief Executive Officer of Akastor ASA

Key filing fact

Asa Akastor filed Form 4 for HMH Holding Inc (HMH) on 02 Apr 2026.

Key facts

This page summarizes Asa Akastor's Form 4 filing for HMH Holding Inc (HMH).
8 reported transactions and 24 derivative rows are listed below.
Accepted by SEC: 02 Apr 2026, 16:19.

Change

Previous filing in this sequence was filed on 31 Mar 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (4)

CIK 0002037057 Primary reporting owner

Akastor ASA

Relationship: 10%+ Owner
Address: OKSENOYVEIEN 10, LYSAKER, NORWAY
Signature: /s/ Karl Erik Kjelstad, as Chief Executive Officer of Akastor ASA
Signature date: 02 Apr 2026

CIK 0002124921

Akastor AS

Relationship: Director, Director by Deputization, 10%+ Owner
Address: OKSENOYVEIEN 10, LYSAKER, NORWAY
Signature: /s/ Oyvind Paaske, Chair of Akastor AS
Signature date: 02 Apr 2026

CIK 0002124920

Mercury HoldCo AS

Relationship: 10%+ Owner
Address: OKSENOYVEIEN 10, LYSAKER, NORWAY
Signature: /s/ Oyvind Paaske, Chair of Mercury HoldCo AS
Signature date: 02 Apr 2026

CIK 0002124922

Mercury HoldCo Inc.

Relationship: Director, Director by Deputization, 10%+ Owner
Address: 3300 NORTH SAM HOUSTON PARKWAY EAST, HOUSTON
Signature: /s/ Askel Matre, Director of Mercury HoldCo Inc.
Signature date: 02 Apr 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

HMH transaction

Class B common stock

Other

Transaction value
Shares: +8,144,374
Change %
Price: $0.000000^*
Shares after: 8,144,374
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc. See footnotes
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction

Class B common stock

Other

Transaction value
Shares: +8,144,374
Change %
Price: $0.000000^*
Shares after: 8,144,374
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc. See footnotes
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction

Class B common stock

Other

Transaction value
Shares: +8,144,374
Change %
Price: $0.000000^*
Shares after: 8,144,374
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc. See footnotes
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction

Class B common stock

Other

Transaction value
Shares: +8,144,374
Change %
Price: $0.000000^*
Shares after: 8,144,374
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc. See footnotes
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction

Class B common stock

Other

Transaction value
Shares: +8,144,374
Change %: +100%
Price: $0.000000^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Akastor AS See footnotes
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction

Class B common stock

Other

Transaction value
Shares: +8,144,374
Change %: +100%
Price: $0.000000^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Akastor AS See footnotes
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction

Class B common stock

Other

Transaction value
Shares: +8,144,374
Change %: +100%
Price: $0.000000^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Akastor AS See footnotes
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction

Class B common stock

Other

Transaction value
Shares: +8,144,374
Change %: +100%
Price: $0.000000^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Akastor AS See footnotes
Footnotes: F1, F2, F3, F4, F5, F6

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

HMH transaction Derivative

B.V. Voting Class A Shares

Other

Transaction value
Shares: -1,050,000
Change %: -6.1%
Price: $9.40^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc.
Underlying class: Class A common stock
Underlying amount: 1,050,000
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class A Shares

Other

Transaction value
Shares: -1,050,000
Change %: -6.1%
Price: $9.40^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc.
Underlying class: Class A common stock
Underlying amount: 1,050,000
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class A Shares

Other

Transaction value
Shares: -1,050,000
Change %: -6.1%
Price: $9.40^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc.
Underlying class: Class A common stock
Underlying amount: 1,050,000
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class A Shares

Other

Transaction value
Shares: -1,050,000
Change %: -6.1%
Price: $9.40^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc.
Underlying class: Class A common stock
Underlying amount: 1,050,000
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class B Shares

Other

Transaction value
Shares: -1,050,000
Change %: -6.1%
Price: $9.40^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Akastor AS
Underlying class: Class A common stock
Underlying amount: 1,050,000
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class B Shares

Other

Transaction value
Shares: -1,050,000
Change %: -6.1%
Price: $9.40^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Akastor AS
Underlying class: Class A common stock
Underlying amount: 1,050,000
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class B Shares

Other

Transaction value
Shares: -1,050,000
Change %: -6.1%
Price: $9.40^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Akastor AS
Underlying class: Class A common stock
Underlying amount: 1,050,000
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class B Shares

Other

Transaction value
Shares: -1,050,000
Change %: -6.1%
Price: $9.40^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Akastor AS
Underlying class: Class A common stock
Underlying amount: 1,050,000
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class A Shares

Other

Transaction value
Shares: -16,288,748
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc.
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class A Shares

Other

Transaction value
Shares: -16,288,748
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc.
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class A Shares

Other

Transaction value
Shares: -16,288,748
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc.
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class A Shares

Other

Transaction value
Shares: -16,288,748
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc.
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class B Shares

Other

Transaction value
Shares: -16,288,748
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 02 Apr 2026
Ownership: Akastor AS
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class B Shares

Other

Transaction value
Shares: -16,288,748
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 02 Apr 2026
Ownership: Akastor AS
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class B Shares

Other

Transaction value
Shares: -16,288,748
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 02 Apr 2026
Ownership: Akastor AS
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Voting Class B Shares

Other

Transaction value
Shares: -16,288,748
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 02 Apr 2026
Ownership: Akastor AS
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Non-Voting Class A Shares

Other

Transaction value
Shares: +16,288,748
Change %
Price: $0.000000^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc.
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Non-Voting Class A Shares

Other

Transaction value
Shares: +16,288,748
Change %
Price: $0.000000^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc.
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Non-Voting Class A Shares

Other

Transaction value
Shares: +16,288,748
Change %
Price: $0.000000^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc.
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Non-Voting Class A Shares

Other

Transaction value
Shares: +16,288,748
Change %
Price: $0.000000^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Mercury HoldCo Inc.
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Non-Voting Class B Shares

Other

Transaction value
Shares: +16,288,748
Change %
Price: $0.000000^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Akastor AS
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Non-Voting Class B Shares

Other

Transaction value
Shares: +16,288,748
Change %
Price: $0.000000^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Akastor AS
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Non-Voting Class B Shares

Other

Transaction value
Shares: +16,288,748
Change %
Price: $0.000000^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Akastor AS
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

HMH transaction Derivative

B.V. Non-Voting Class B Shares

Other

Transaction value
Shares: +16,288,748
Change %
Price: $0.000000^*
Shares after: 16,288,748
Date: 02 Apr 2026
Ownership: Akastor AS
Underlying class: Class A common stock
Underlying amount: 16,288,748
Exercise price
Footnotes: F1, F2, F3, F4, F5, F6

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 6 footnotes

Footnote F1

Prior to the initial public offering ("IPO") of HMH Holding Inc. (the "Issuer"), (a) Akastor AS, a direct wholly owned subsidiary of Akastor ASA, held 50 Class B ordinary shares (the "B.V. Voting Class B Shares") of HMH Holding B.V. ("HMH B.V.") and (b) Mercury HoldCo Inc., an indirect wholly owned subsidiary of Akastor ASA (with Mercury HoldCo AS as an intermediary subsidiary between Akastor ASA and Mercury HoldCo Inc.) held 50 Class A ordinary shares (the "B.V. Voting Class A Shares") of HMH B.V. In this filing, Akastor ASA, Akastor AS, Mercury HoldCo AS and Mercury HoldCo Inc. are collectively referred to as "Akastor". (cont'd in fn 2)

Footnote F2

(cont'd from fn 1) In connection with the corporate reorganization and Akastor's participation in the synthetic secondary as described in the Issuer's Registration Statement on Form S-1 (Registration No. 333-281497), the following transactions have occurred: first, HMH B.V., the predecessor entity to the Issuer, underwent a 346,774.96 for 1 stock split, after which Akastor held 17,338,748 B.V. Voting Class B Shares (through Akastor AS) and 17,338,748 B.V. Voting Class A Shares (through Mercury HoldCo Inc.); second, HMH B.V. recapitalized to convert (i) 16,288,748 of Mercury HoldCo Inc.'s B.V. Voting Class A Shares to non-voting Class A ordinary shares (the "B.V. Non-Voting Class A Shares") and (ii) 16,288,748 of Akastor AS's B.V. Voting Class B Shares to non-voting Class B ordinary shares (the "B.V. Non-Voting Class B Shares"); (cont'd in fn 3)

Footnote F3

(cont'd from fn. 2) third, (i) Akastor AS sold 1,050,000 B.V. Voting Class B Shares, and Mercury HoldCo Inc. sold 1,050,000 B.V. Voting Class A Shares, in each case, to the Issuer in exchange cumulatively for $19,740,000 and (ii) each of Akastor AS and Mercury HoldCo Inc. received 8,144,374 shares of Class B common stock of the Issuer (the "Issuer Class B Shares") in exchange for relinquishing voting rights on their respective remaining 16,288,748 B.V. Voting Class B Shares (held by Akastor AS) and 16,288,748 B.V. Voting Class A Shares (held by Mercury HoldCo Inc.) that were recapitalized into 16,288,748 B.V. Non-Voting Class B Shares (held by Akastor AS) and 16,288,748 B.V. Non-Voting Class A Shares (held by Mercury HoldCo Inc.), respectively.

Footnote F4

Akastor ASA has an indirect pecuniary interest in the securities held by each of Akastor AS and Mercury HoldCo Inc. Mercury HoldCo AS has an indirect pecuniary interest in the securities held by Mercury HoldCo Inc. Consequently, Akastor ASA may be deemed to share beneficial ownership in the securities held directly by Akastor AS, and Akastor ASA and Mercury HoldCo AS may be deemed to share beneficial ownership in the securities held directly by Mercury HoldCo Inc. The board of directors and officers of Akastor ASA, Mercury HoldCo Inc., Akastor AS and Mercury HoldCo AS disclaim beneficial ownership with respect to such securities.

Footnote F5

Pursuant to the Exchange Agreement, dated as of April 2, 2026, by and among the Issuer, HMH B.V. and the other parties thereto, Akastor has the right to exchange one Issuer Class B Share, one B.V. Non-Voting Class A Share and one B.V. Non-Voting Class B Share for cash or shares of the Issuer's Class A common stock on a one-for-one basis, subject to customary conversion rate adjustments (e.g. for stock splits, stock dividends and reclassifications). These rights are exercisable at any time after the conclusion of the Issuer's IPO lock-up period (i.e., September 27, 2026, unless the IPO lock-up is earlier released or waived by the underwriters of the Issuer's IPO) and do not expire.

Footnote F6

Karl Erik Kjelstad and Svein Oskar Stoknes are directors of the Issuer and were nominated for such roles by Akastor AS and Mercury HoldCo Inc. By virtue of their service on the Board of Directors of the Issuer, for purposes of Section 16, Akastor AS and Mercury HoldCo Inc. may be deemed to be a "director by deputization" of the Issuer.