Frederick W. Buckman - 09 Oct 2026 Form 4 Insider Report for Terrestrial Energy Inc. /DE/ (IMSR)

Reporting relationship: Director
Issuer ticker: IMSR
Reported as of: 09 Oct 2026
Net transaction value: +$39,336
SEC form: 4
Accepted by SEC: 13 Oct 2026, 11:06:12 UTC
Prior SEC filing: 22 Dec 2025
Source filing: View source filing
Reporting owner signature: /s/ Brian Thrasher, as Attorney-in-Fact

Filing notes and source

Key filing fact

Frederick W. Buckman filed Form 4 for Terrestrial Energy Inc. /DE/ (IMSR) on 13 Oct 2026.

Key facts

This page summarizes Frederick W. Buckman's Form 4 filing for Terrestrial Energy Inc. /DE/ (IMSR).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 13 Oct 2026, 11:06.

Change

Previous filing in this sequence was filed on 22 Dec 2025.
Current net transaction value: +$39,336.

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 (1)

CIK 0001144845 Primary reporting owner

BUCKMAN FREDERICK W

Relationship: Director
Address: C/O TERRESTRIAL ENERGY INC., 2730 W. TYVOLA ROAD, SUITE 100, CHARLOTTE
Signature: /s/ Brian Thrasher, as Attorney-in-Fact
Signature date: 13 Oct 2026

Reported non-derivative transactions

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

IMSR transaction

Common Stock

Purchase

Transaction value: $39,336
Shares: +12,000
Change %: +180%
Price: $3.28
Shares after: 18,669
Date: 09 Oct 2026
Ownership: Direct

IMSR holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 14,930
Date: 09 Oct 2026
Ownership: Through Trust

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

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