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Terrestrial Energy Inc.

IMSRW
Exchange
Nasdaq
Industry
Fabricated Plate Work (Boiler Shops)
SEC CIK
0002019804

No open-market purchases or sales by Terrestrial Energy Inc. insiders were filed in the last 90 days; 24 institutions reported holding it in 13F filings for Q2 2026, worth $39.8M in total; no superinvestor holds it.

Other share classesIMSR

13F holders, Q3 2025

Institutional positions in Terrestrial Energy Inc. as of Sep 30, 2025. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works

Institutional holders
24
−6 vs. Q2 2025
Shares held
9.54M
−2.20M (−18.8%) vs. Q2 2025
Total value
$57.3M
+$29.9M (+108.7%) vs. Q2 2025
New holders
8
4 more added
Sold out
14
7 more reduced

1 institution that held it in Q2 2025 haven't filed for Q3 2025 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.

Compare with Q2 2025: new holders, sold out and not filed yet

Holders and value by quarter

Institutions reporting IMSRW on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.

Institutional holdersQ3 2025: 24 institutions
Q1 2021: 0 institutionsQ2 2021: 0 institutionsQ3 2021: 0 institutionsQ4 2021: 0 institutionsQ1 2022: 0 institutionsQ2 2022: 0 institutionsQ3 2022: 0 institutionsQ4 2022: 0 institutionsQ1 2023: 0 institutionsQ2 2023: 0 institutionsQ3 2023: 0 institutionsQ4 2023: 0 institutionsQ1 2024: 0 institutionsQ2 2024: 0 institutionsQ3 2024: 0 institutionsQ4 2024: 23 institutionsQ1 2025: 30 institutionsQ2 2025: 31 institutionsQ3 2025: 24 institutionsQ4 2025: 28 institutionsQ1 2026: 26 institutionsQ2 2026: 24 institutions
Value heldQ3 2025: $57.3M
Q1 2021: $0Q2 2021: $0Q3 2021: $0Q4 2021: $0Q1 2022: $0Q2 2022: $0Q3 2022: $0Q4 2022: $0Q1 2023: $0Q2 2023: $0Q3 2023: $0Q4 2023: $0Q1 2024: $0Q2 2024: $0Q3 2024: $0Q4 2024: $767.9KQ1 2025: $8.04MQ2 2025: $27.6MQ3 2025: $57.3MQ4 2025: $23.1MQ1 2026: $29.6MQ2 2026: $39.8M
Institutions holding IMSRW and their total value by quarter
QuarterHoldersValue
Q2 202624$39.8M
Q1 202626$29.6M
Q4 202528$23.1M
Q3 202524$57.3M
Q2 202531$27.6M
Q1 202530$8.04M
Q4 202423$767.9K
Q3 20240$0
Q2 20240$0
Q1 20240$0
Q4 20230$0
Q3 20230$0
Q2 20230$0
Q1 20230$0
Q4 20220$0
Q3 20220$0
Q2 20220$0
Q1 20220$0
Q4 20210$0
Q3 20210$0
Q2 20210$0
Q1 20210$0

Institutions, Q3 2025

Shares, value and share of portfolio for each institution holding Terrestrial Energy Inc.; share changes are against Q2 2025.

Institutions holding IMSRW in Q3 2025
InstitutionSharesValue% of portfolioChange in sharesAction
Cantor Fitzgerald, L. P.2,724,172$16.3M0.32%−91,161−3.2%Reduced
LMR Partners LLP1,602,973$9.62M0.12%+52,900+3.4%Added
PEAK6 LLC1,169,212$7.02M0.18%+594,124+103.3%Added
Magnetar Financial LLC674,999$4.09M0.02%−305,100−31.1%Reduced
Balyasny Asset Management LLC660,000$4.00M0.01%+85,000+14.8%Added
Linden Advisors LP450,000$2.72M0.02%−50,000−10.0%Reduced
Arosa Capital Management LP450,000$2.70M4.15%00.0%Unchanged
Morgan Stanley283,078$1.70M0.00%00.0%Unchanged
MYDA Advisors LLC281,000$1.69M0.51%+141,697+101.7%Added
Aristeia Capital LLC229,314$1.38M0.04%+229,314New
CNH Partners LLC241,236$1.32M0.03%−875,692−78.4%Reduced
Whitebox Advisors LLC200,000$1.20M0.02%00.0%Unchanged
CastleKnight Management LP153,200$928.4K0.05%+153,200New
BNP Paribas Arbitrage, SA99,332$596.0K0.00%+99,332New
Meteora Capital, LLC70,200$421.2K0.04%+70,200New
Picton Mahoney Asset Management59,282$355.0K0.00%−505,000−89.5%Reduced
Rivernorth Capital Management, LLC49,700$298.2K0.02%−150,300−75.1%Reduced
Saba Capital Management, L.P.48,932$295.3K0.01%00.0%Unchanged
Mint Tower Capital Management B.V.33,505$201.0K0.03%−38,946−53.8%Reduced
Boothbay Fund Management, LLC11,476$188.3K0.00%+11,476New
Clear Street Group Inc.30,000$180.0K0.00%+30,000New
Fulton Breakefield Broenniman LLC18,405$110.4K0.01%00.0%Unchanged
Royal Bank of Canada500$3.00K0.00%+500New
Bank of America Corp308$1.85K0.00%+308New
MMCAP International Inc. SPC0$00.00%−490,000−100.0%Sold out
Calamos Advisors LLC0$00.00%−250,000−100.0%Sold out
K2 Principal Fund, L.P.0$00.00%−177,489−100.0%Sold out
Governors Lane LP0$00.00%−141,101−100.0%Sold out
CSS LLC0$00.00%−123,216−100.0%Sold out
Gritstone Asset Management LLC0$00.00%−111,926−100.0%Sold out
Tenor Capital Management Co., L.P.0$00.00%−87,500−100.0%Sold out
Polar Asset Management Partners Inc.0$00.00%−80,763−100.0%Sold out
Context Capital Management, LLC0$00.00%−74,868−100.0%Sold out
Periscope Capital Inc.0$00.00%−32,500−100.0%Sold out
Wolverine Asset Management LLC0$00.00%−31,055−100.0%Sold out
Bulldog Investors, LLP0$00.00%−25,000−100.0%Sold out
Parallax Volatility Advisers, L.P.0$00.00%−15,078−100.0%Sold out
Schonfeld Strategic Advisors LLC0$00.00%−14,997−100.0%Sold out
Clear Street LLC––––Not filed