Shawn Matthews - 28 Oct 2025 Form 4 Insider Report for Terrestrial Energy Inc. /DE/ (IMSR)

Role
Director
Signature
/s/ Shawn Matthews, by Steven Bishcoff, Attorney-in-Fact
Issuer symbol
IMSR
Transactions as of
28 Oct 2025
Transactions value $
-$63,739,889
Form type
4
Filing time
30 Oct 2025, 20:31:15 UTC
Previous filing
17 Oct 2025
Next filing
13 Nov 2025
SEC
View on sec.gov

Reporting Owners (2)

Name Relationship Address Signature Signature date CIK
Matthews Shawn Director C/O HCM INVESTOR HOLDINGS II, LLC, 100 FIRST STAMFORD PLACE, SUITE 330, STAMFORD /s/ Shawn Matthews, by Steven Bishcoff, Attorney-in-Fact 30 Oct 2025 0001855118
HCM Investor Holdings II, LLC Former 10% owner C/O HCM INVESTOR HOLDINGS II, LLC, 100 FIRST STAMFORD PLACE, SUITE 330, STAMFORD /s/ HCM Investor Holdings II, LLC, by Steven Bischoff, Attorney-in-Fact 30 Oct 2025 0002019800

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction IMSR Common Stock, par value $0.0001 per share Other +5.68M 5.68M 28 Oct 2025 See Footnote F1, F2
transaction IMSR Common Stock, par value $0.0001 per share Other +534K 534K 28 Oct 2025 Direct F3

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction IMSR Warrants Other -$49.2M -4.28M -50% $11.50 4.28M 28 Oct 2025 Common Stock, par value $0.0001 per share 4.28M $11.50 See Footnote F2
transaction IMSR Warrants Other -$14.6M -1.27M -50% $11.50 1.27M 28 Oct 2025 Common Stock, par value $0.0001 per share 1.27M $11.50 See Footnote F4
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 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, dated March 26, 2025 and as amended on October 28, 2025, by and among HCM II, Terrestrial and HCM II Merger Sub Inc. (the "BCA"). The reporting person resigned as an officer of HCM II upon the closing of the Business Combination.
F2 Mr. Matthews is the sole managing member of HCM Investor Holdings II, LLC (the "Sponsor"), which is registered owner of these shares and warrants, and Mr. Matthews holds voting and investment power with respect to shares and warrants held of record by the Sponsor.
F3 Upon closing of the Business Combination, between Terrestrial Energy Inc., a Delaware corporation formerly known as HCM II Acquisition Corp. ("New Terrestrial"), and Terrestrial Energy Development Inc., a Delaware corporation formerly known as Terrestrial Energy Inc. ("Legacy Terrestrial"), the reporting person acquired these securities in exchange for the reporting person's securities in Legacy Terrestrial pursuant to the terms and conditions of the BCA.
F4 Mr. Matthews is the sole managing member of Hondo Holdings LLC, which is registered owner of these warrants, and Mr. Matthews holds voting and investment power with respect to warrants held of record by Hondo Holdings LLC.