Form 4: 25,000-share insider acquisition at Terrestrial Energy

Rhea-AI Filing Summary

Terrestrial Energy Inc. reported an insider acquisition on a Form 4. On 10/28/2025, the reporting person acquired 25,000 shares of common stock (Transaction Code J) in connection with the closing of a business combination between HCM II Acquisition Corp. and Terrestrial Energy Inc., receiving shares in exchange under the business combination agreement.

Following the transaction, the insider beneficially owns 25,000 shares, held directly. The filing notes the reporting person resigned as a director of HCM II upon closing.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Connor Michael J

Role Insider

Type	Security	Shares	Price	Value
Other	Common Stock, par value $0.0001 per share	25,000	$0.00	--

Holdings After Transaction: Common Stock, par value $0.0001 per share — 25,000 shares (Direct)

Footnotes (1)

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Form 4 Insider Transactions: What Each Field Means →

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

X

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^*

Connor Michael J

(Last) (First) (Middle)

C/O HCM INVESTOR HOLDINGS II, LLC

100 FIRST STAMFORD PLACE, SUITE 330

(Street)

STAMFORD CT 06902

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Terrestrial Energy Inc. /DE/ [ IMSR ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
10/28/2025

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)
			Code	V	Amount	(A) or (D)	Price
Common Stock, par value $0.0001 per share	10/28/2025		J		25,000	A	(1)	25,000	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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Upon closing of the business combination (the "Business Combination") between the Issuer (which was formerly known as HCM II Acquisition Corp. or "HCM II") and Terrestrial Energy Inc. ("Terrestrial") the reporting person acquired these securities in exchange for the reporting person's securities in Terrestrial pursuant to the terms and conditions of the business combination agreement, by and among HCM, Terrestrial and HCM II Merger Sub Inc. (the "BCA"). The reporting person resigned as a director of HCM II upon the closing of the Business Combination.

	/s/ Michael Connor, by Steven Bishcoff, Attorney-in-Fact	10/30/2025
	** 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.

FAQ

What did HOND report on this Form 4?

An insider acquired 25,000 shares of Terrestrial Energy Inc. common stock on 10/28/2025 via a business combination exchange.

What is the transaction code and what does it mean?

The transaction code is J, which indicates an acquisition under other circumstances, here tied to a business combination exchange.

How many shares does the insider own after the transaction?

The insider beneficially owns 25,000 shares after the reported transaction.

Was this a market purchase or part of a merger exchange?

It was part of a business combination exchange between HCM II Acquisition Corp. and Terrestrial Energy Inc., per the agreement.

What is the ownership form of the reported shares?

The shares are held directly by the reporting person.

Did the filing mention any board changes?

Yes. The reporting person resigned as a director of HCM II upon the business combination closing.