SEC Form SCHEDULE 13D filed by HCM II Acquisition Corp.

The Reporting Person's address is 2730 W. Tyvola Road, Suite 100, Charlotte, NC 28217

The Reporting Person is the Chief Executive Officer and a director of the Issuer.

During the last five years, the Reporting Person has not been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

During the last five years, the Reporting Person has not been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

United States

All of the shares of Common Stock reported herein as beneficially owned by the Reporting Person were acquired pursuant to a Business Combination Agreement, dated March 26, 2025 (as amended from time to time, the "Business Combination Agreement"), by and among the Issuer (which was formerly known as HCM II Acquisition Corp. or "HCM II"), HCM II Merger Sub Inc., a Delaware corporation and a direct wholly owned subsidiary of HCM II ("Merger Sub"), and Terrestrial Energy Development Inc., a Delaware corporation (formerly known as Terrestrial Energy Inc., or "Legacy Terrestrial"). Pursuant to the terms of the Business Combination Agreement, Merger Sub merged with and into Legacy Terrestrial, with Legacy Terrestrial surviving as the surviving company and as a wholly owned subsidiary of Issuer (the "Merger" and, collectively with the other transactions described in the Business Combination Agreement, the "Business Combination"). The Business Combination closed on October 28, 2025 (the "Closing"). In connection with Closing, and subject to the terms and conditions of the Business Combination Agreement, among other things, (i) each share of Legacy Terrestrial's common stock issued and outstanding immediately prior to the effective time of the Merger was cancelled and converted into the right to receive a number of shares of the Issuer's common stock equal to the Exchange Ratio (the "Per Share Merger Consideration"), (ii) each share of Legacy Terrestrial's preferred stock designated as "Series A Preferred Stock" or "Series A-1 Preferred Stock" that was issued and outstanding immediately prior to the effective time of the Merger was cancelled and converted into the right to receive a number of shares of the Issuer's common stock equal to the (A) the number of Legacy Terrestrial's common stock into which such Legacy Terrestrial's preferred shares were converted in accordance with Legacy Terrestrial's governing documents as of immediately prior to the effective time; multiplied by (B) the Per Share Merger Consideration, (ii) each outstanding and unexercised option to purchase shares of Legacy Terrestrial common stock (a "Legacy Terrestrial Option"), whether vested or unvested, issued and outstanding immediately prior to the Closing was automatically assumed by the Issuer such that, as of the effective time, each share underlying each Legacy Terrestrial Option became the Issuer's common stock and the number of such shares were equal to the Exchange Ratio, and (iv) each warrant to purchase shares or other equity interests of Legacy Terrestrial (each, a "Legacy Terrestrial Warrant") that was outstanding and unexercised immediately prior to the effective time was assumed by the Issuer and became exercisable, in accordance with the terms and conditions of such Legacy Terrestrial Warrant, for the Per Share Base Consideration. Capitalized terms used in this Schedule 13D but not defined herein, or for which definitions are not otherwise incorporated by reference herein, shall have the meanings given to such terms in the Current Report on Form 8-K filed by the Issuer with the Securities and Exchange Commission on November 3, 2025.

The Reporting Person acquired the shares reported herein for investment purposes and to incentivize him in connection with his employment with the Issuer. To the extent required by Item 4, the information contained in Item 3 and Item 6 is incorporated herein by reference. The Reporting Person serves as Chief Executive Officer of the Issuer and as a member of the Issuer's Board of Directors and, in such capacities, may have influence over the corporate activities of the Issuer, including activities that may relate to items described in subparagraphs (a) through (j) of Item 4 of Schedule 13D. Subject to the that certain Lock-Up Agreement, as described in Item 6 of this Schedule 13D, and the Issuer's Insider Trading Policy (the "Insider Trading Policy"), the Reporting Person may from time to time buy or sell securities of the Issuer as appropriate for his personal circumstances. Except as described herein, the Reporting Person does not have any present plans or proposals that relate to or would result in any of the transactions described in subparagraphs (a) through (j) of Item 4 of Schedule 13D. However, the Reporting Person reserves the right to formulate in the future plans or proposals that may relate to or result in the transactions described in subparagraphs (a) through (j) of Item 4 of Schedule 13D. The Reporting Person may, from time to time, purchase additional securities of the Issuer either in the open market or in privately negotiated transactions, depending upon the Reporting Person's evaluation of the Issuer's business, prospects and financial condition, the market for such securities, other opportunities available to the Reporting Person, general economic conditions, stock market conditions and other factors. Depending upon the factors noted above, the Reporting Person may also decide to hold or dispose of all or part of his investments in securities of the Issuer and/or enter into derivative transactions with institutional counterparties with respect to the Issuer's securities, subject to the limitations under the Lock-Up, Insider Trading Policy and securities law.

The information set forth in rows (7) through (13) of the cover pages of this Schedule 13D is incorporated by reference into this Item 5(a).

The information set forth in rows (7) through (10) of the cover pages of this Schedule 13D is incorporated by reference into this Item 5(b).

Except as set forth herein, no transactions in the Common Stock were effected by the Reporting Person during the past 60 days.

Not applicable.

Not applicable.

To the extent required by Item 6, the information contained in Item 3 is incorporated herein by reference. On the Closing Date, the Reporting Person entered into a voting co-ordination agreement (the "Voting Agreement") with Dr. David LeBlanc, a stockholder of the Issuer and its Chief Technology Officer, pursuant to which to the extent Mr. LeBlanc would otherwise be entitled to cast more votes, on any matter submitted to stockholders of the Issuer, than Mr. Irish, Mr. LeBlanc has granted Mr. Irish the power to direct the voting of such excess shares. Giving effect to such arrangement, as of the date of this report, Mr. Irish also has sole voting power with respect to an additional 3,014,391 shares beneficially owned by Mr. LeBlanc. The foregoing description is qualified in its entirety by the text of the Voting Agreement, which is included as an exhibit under Item (7) and is incorporated herein by reference. On the Closing Date the Reporting Person entered into a lock-up agreement (the "Lock-Up Agreement") with the Issuer, pursuant to which the Reporting Person agreed to restrictions on transfer for up to one year following the Closing Date with respect to the Lock-Up Shares (as defined in the Lock-Up Agreement), which lock-up, subject to certain exceptions and permitted transfers, including but not limited to, transfers to certain affiliates or family members, or the exercise of certain stock options and warrants. The Lock-Up Agreements further provide that following the 180th day following the Closing, (a) fifty percent (50%) of the Key Holder Lock-Up Shares may be transferred once the dollar volume-weighted average adjusted price for the New Terrestrial Common Shares calculated as an average for the prior twenty Business Days (the "VWAP") equals or exceeds $15.00 per share, and (b) all of the Key Holder Lock-Up Shares may be transferred once the VWAP equals or exceeds $20.00 per share. The foregoing description is qualified in its entirety by the text of the Lock Up Agreement, which is included as an exhibit under Item (7) and is incorporated herein by reference.

Exhibit 1: Form of Lock-Up Agreement, by and among HCM II Acquisition Corp. and the other parties thereto (incorporated by reference to Exhibit 10.5 to the Current Report on Form 8-K filed by the Issuer with the Securities and Exchange Commission on November 3, 2025). Exhibit 2: Voting Co-ordination Agreement dated October 28, 2025, by and between Dr. David LeBlanc and Simon Irish.