Terrestrial Energy Inc.
IMSR- Exchange
- Nasdaq
- Industry
- Fabricated Plate Work (Boiler Shops)
- SEC CIK
- 0002019804
In the last 90 days, Terrestrial Energy Inc. insiders filed 3 open-market purchases and 0 sales; 110 institutions reported holding it in 13F filings for Q2 2026, worth $151.3M in total; no superinvestor holds it.
Other share classesIMSRW
Open-market trades, last 90 days
Open-market purchases (P) and sales (S) by Terrestrial Energy Inc. insiders, counted by Form 4 filing. Trades with a flagged price and duplicate filings are left out.
- Open-market buys
- 3 filings
- 3 insiders, $112.3K in total
- Open-market sells
- 0 filings
- Insiders trading
- 3
- Net value
- +$112.3K
- Purchases minus sales
Insider roster
Directors, officers and 10% owners who have filed a Form 4 for Terrestrial Energy Inc., current and former, most recent filer first. Last reported holding is the position after the last non-derivative trade in their latest filing.
| Name | Title | Last reported holding | Last filing | Filings, past year |
|---|---|---|---|---|
| Irish Simon | Chief Executive Officer | 2,879,846 | Oct 30, 2026 | 3 |
| Williams David Woodward | Chief Commercial Officer | – | Oct 21, 2026 | 1 |
| Pardee Charles G | Director | 14,258 | Oct 15, 2026 | 2 |
| Buckman Frederick W | Director | 18,669 | Oct 13, 2026 | 2 |
| Cowan Pamela Beth | EVP, Engineering | – | Jul 31, 2026 | 1 |
| McCarthy Kathryn Ann | Director | – | Jul 27, 2026 | 1 |
| Millsap Steven M. | General Counsel | – | Apr 14, 2026 | 1 |
| Thrasher Brian Patrick | Chief Financial Officer | – | Apr 14, 2026 | 1 |
| Smith William F. | Chief Operating Officer | – | Apr 14, 2026 | 1 |
| LeBlanc David Michael | Chief Technology Officer | – | Apr 14, 2026 | 1 |
| Johnson William D | Director | – | Jan 9, 2026 | 1 |
| Jones Robert Wood | Director | – | Dec 22, 2025 | 1 |
| Matthews Shawn | Director | 2,755,000Indirect | Dec 22, 2025 | 2 |
| Hill David John | Director | – | Dec 22, 2025 | 1 |
| MacDiarmid John Hugh | Director | – | Dec 22, 2025 | 1 |
| HCM Investor Holdings II, LLC | Other: Former 10% Holder | 2,755,000Indirect | Nov 13, 2025 | 1 |
| Loveless Jacob | Other: Former Director | 25,000 | Oct 30, 2025 | 0 |
| Connor Michael J | Other: Former Director | 25,000 | Oct 30, 2025 | 0 |
| Brenner Andrew Scott | Other: Former Director | 25,000 | Oct 30, 2025 | 0 |
Insider trades
Each row adds up one type of transaction in one Form 4 filing. Only open-market purchases (P) and sales (S) are shown by default; use the filters to see grants, option exercises and other codes.
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Oct 15, 2026 (view filing)5:42 PM ET | Oct 14 | 1 day | Pardee Charles GDirector | PPurchase | +7.50K | $2.95 | +$22.1K | +111.0%14.3K after | |
| Oct 14, 2026 (view filing)9:15 AM ET | Oct 13 | 1 day | Irish SimonChief Executive Officer | PPurchase | +16.9K | $3.01 | +$50.8K | +0.7%2.31M after | |
| Oct 13, 2026 (view filing)11:06 AM ET | Oct 9 | 4 days | Buckman Frederick WDirector | PPurchase | +12.0K | $3.28 | +$39.3K | +179.9%18.7K after |