Terrestrial Energy Inc. (IMSR)
Nasdaq: IMSR · Fabricated Plate Work (Boiler Shops) · Charlotte, NC · filing with the SEC since 2024
Who owns Terrestrial Energy Inc.
As filed with the SECHolders of 5% or more
4
Roberto Marco Sella holds 14.3% of Common Stock, par value $0.0001 per share, as its SCHEDULE 13G filed Jan 22, 2026 says.
Directors and officers
18
report now, of 19 people on the record since 2024. Their holdings as a group are not read here.
Institutions as a whole
n/a
The record does not read the share held by managers that file Form 13F, so none is printed and no split of the rest is estimated. What it holds is the 4 named at left.
Holders of 5% or moreshare of the class, as filed
Roberto Marco Sella
SCHEDULE 13G · filed Jan 22, 2026 · Common Stock, par value $0.0001 per share
Simon Irish
SCHEDULE 13D · filed Nov 4, 2025 · Common Stock
David LeBlanc
SCHEDULE 13D · filed Nov 4, 2025 · Common Stock
Barclays PLC
SCHEDULE 13G/A · filed Mar 21, 2025 · COMMON-STOCK · 6.17% in Feb 7, 2025
First Trust Capital Management L.P.
SCHEDULE 13G/A · filed Aug 14, 2025 · Class A Ordinary Shares, par value $0.0001 per share ("Ordinary Shares") · reported falling below 5%, from 7.6% in May 15, 2025
LMR Partners LLP
SCHEDULE 13G/A · filed Aug 14, 2025 · Class A Ordinary Shares, par value $0.0001 per share · reported falling below 5%
Picton Mahoney Asset Management
SCHEDULE 13G/A · filed Aug 6, 2025 · Class A Ordinary Shares · reported falling below 5%, from 8.61% in Feb 11, 2025
Merus Global Investments, LLC
SCHEDULE 13G/A · filed Aug 14, 2025 · Class A Ordinary Shares, par value $0.0001 per share · reported falling below 5%, from 6.4% in Jun 2, 2025
Goldman Sachs Group Inc.
SCHEDULE 13G/A · filed May 12, 2025 · Class A ordinary shares, par value $0.0001 per share · reported falling below 5%, from 5.2% in Feb 12, 2025
Kenneth Griffin
SCHEDULE 13G/A · filed Feb 17, 2026 · Common stock, par value $0.0001 per share (the "Shares") · reported falling below 5%, from 5.4% in Sep 30, 2025
Linden Capital L.P.
SCHEDULE 13G/A · filed Nov 12, 2025 · Common Stock, par value $0.0001 per share · reported falling below 5%, from 8.7% in Mar 31, 2025
Magnetar Financial LLC
SCHEDULE 13G/A · filed Nov 12, 2025 · Common Stock, par value $0.0001 · reported falling below 5%, from 6.07% in Aug 8, 2025
AQR Capital Management, LLC
SCHEDULE 13G/A · filed Aug 13, 2025 · Class A Ordinary Shares, par value $0.0001 per share · reported falling below 5%, from 5.6% in May 14, 2025
What IMSR reports owning in othersstakes of 5% or more, and other ties
Other ties the annual report names
Terrestrial Energy Delaware Inc
An entity · consolidated entity · owns, named in the 10-K filed Mar 30, 2026
Terrestrial Energy Development, Inc
An entity · legal entity · owns, named in the 10-K filed Mar 30, 2026
HCM II Acquisition Corp
A company bought · acquisition · owns, named in the 10-K filed Mar 30, 2026
Insider tradesForm 4
0sales
3purchases
0sales on a scheduled plan
0people selling
$0sold, in dollars
$100,000bought, in dollars
Open-market trades on Form 4 from Oct 30, 2025 to Oct 30, 2026. A scheduled plan is a selling program set in advance under SEC rule 10b5-1. The trades are listed as filed and do not feed the grade.
By calendar yearSoldBought
2026 runs to Oct 30, 2026. Dollars as filed, summed by the transaction date.
People who traded in the window3 of 21 on the roster
| Person | Role as filed | Sales | Sold | On a plan | Buys | Bought |
|---|---|---|---|---|---|---|
| Irish Simon | Chief Executive Officer | 0 | $0 | 0 | 1 | $100,000 |
| Pardee Charles G | director | 0 | $0 | 0 | 1 | $0 |
| Buckman Frederick W | director | 0 | $0 | 0 | 1 | $0 |