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Terrestrial Energy Inc.

IMSR
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; 110 institutions reported holding it in 13F filings for Q2 2026, worth $151.3M in total; no superinvestor holds it.

Other share classesIMSRW

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
66
+1 vs. Q2 2025
Shares held
9.90M
−8.89M (−47.3%) vs. Q2 2025
Total value
$162.5M
−$47.1M (−22.5%) vs. Q2 2025
New holders
33
14 more added
Sold out
32
18 more reduced

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

Holders and value by quarter

Institutions reporting IMSR 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: 66 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: 35 institutionsQ1 2025: 45 institutionsQ2 2025: 65 institutionsQ3 2025: 66 institutionsQ4 2025: 82 institutionsQ1 2026: 88 institutionsQ2 2026: 110 institutions
Value heldQ3 2025: $162.5M
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: $162.3MQ1 2025: $213.4MQ2 2025: $209.6MQ3 2025: $162.5MQ4 2025: $130.7MQ1 2026: $111.3MQ2 2026: $151.3M
Institutions holding IMSR and their total value by quarter
QuarterHoldersValue
Q2 2026110$151.3M
Q1 202688$111.3M
Q4 202582$130.7M
Q3 202566$162.5M
Q2 202565$209.6M
Q1 202545$213.4M
Q4 202435$162.3M
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 IMSR in Q3 2025
InstitutionSharesValue% of portfolioChange in sharesAction
D. E. Shaw & Co., Inc.1,092,495$17.9M0.01%+122,495+12.6%Added
Citadel Advisors LLC1,030,421$16.9M0.01%+960,700+1,377.9%Added
Balyasny Asset Management LLC864,263$14.2M0.03%+319,369+58.6%Added
LMR Partners LLP725,267$11.9M0.15%−216,020−22.9%Reduced
Millennium Management LLC629,363$10.3M0.01%+429,363+214.7%Added
Susquehanna International Group, LLP601,931$9.88M0.01%+586,785+3,874.2%Added
Vennlight Capital Management, LP500,000$8.21M10.68%−527,934−51.4%Reduced
Cantor Fitzgerald, L. P.341,328$5.60M0.11%−124,959−26.8%Reduced
Davidson Kempner Capital Management LP270,540$4.44M0.06%+270,540New
Sourcerock Group LLC257,900$4.23M0.29%+257,900New
Alyeska Investment Group, L.P.244,672$4.02M0.01%+244,672New
SIR Capital Management, L.P.217,600$3.57M0.32%+217,600New
Linden Advisors LP209,426$3.44M0.02%−1,740,574−89.3%Reduced
HRT Financial LP204,611$3.36M0.01%−25,458−11.1%Reduced
Waratah Capital Advisors Ltd.198,188$3.25M0.22%+198,188New
Moore Capital Management, LP175,000$2.87M0.06%+175,000New
Shay Capital LLC162,146$2.66M0.48%−386,112−70.4%Reduced
Berkley W R Corp160,672$2.64M0.17%−237,349−59.6%Reduced
Magnetar Financial LLC142,304$2.34M0.01%−1,254,862−89.8%Reduced
Jane Street Group, LLC127,190$2.09M0.00%+127,190New
Whitebox Advisors LLC115,000$1.89M0.04%−203,914−63.9%Reduced
BlueCrest Capital Management Ltd110,644$1.82M0.11%+110,644New
Wexford Capital LP102,712$1.69M0.51%+2,712+2.7%Added
HITE Hedge Asset Management LLC102,338$1.68M0.09%+102,338New
Verition Fund Management LLC101,145$1.66M0.01%−48,855−32.6%Reduced
Sona Asset Management (US) LLC100,000$1.64M0.06%+100,000New
Galaxy Group Investments LLC100,000$1.64M0.16%+100,000New
Deltec Asset Management LLC75,000$1.23M0.20%−25,000−25.0%Reduced
Morgan Stanley71,420$1.17M0.00%+451+0.6%Added
Arosa Capital Management LP65,000$1.07M1.64%−495,000−88.4%Reduced
Massar Capital Management, LP65,000$1.07M0.38%−35,000−35.0%Reduced
Jain Global LLC63,363$1.04M0.01%+63,363New
Geode Capital Management, LLC63,146$1.04M0.00%−58,227−48.0%Reduced
Boothbay Fund Management, LLC58,698$963.2K0.02%+58,698New
JPMorgan Chase & Co52,946$868.8K0.00%+3,206+6.4%Added
Simplex Trading, LLC48,514$796.0K0.02%+48,514New
Picton Mahoney Asset Management42,081$691.0K0.01%−900,000−95.5%Reduced
CastleKnight Management LP41,900$687.6K0.04%+41,900New
PEAK6 LLC41,389$679.2K0.02%−211,972−83.7%Reduced
Commonwealth Equity Services, LLC32,571$534.0K0.00%+32,571New
MYDA Advisors LLC30,000$492.3K0.15%−270,000−90.0%Reduced
Alpine Global Management, LLC29,300$480.8K0.10%+29,300New
Bank of America Corp27,552$452.1K0.00%+27,552New
Nations Financial Group Inc,27,047$443.8K0.03%+27,047New
Private Advisor Group, LLC22,841$374.8K0.00%+22,841New
UBS Group AG21,889$359.2K0.00%+18,241+500.0%Added
FNY Investment Advisers, LLC18,520$303.0K0.10%−22,980−55.4%Reduced
Tuttle Tactical Management17,500$287.2K1.09%+2,500+16.7%Added
National Bank of Canada16,698$274.0K0.00%+4,130+32.9%Added
EHP Funds Inc.13,895$228.0K0.30%+13,895New
Maven Securities LTD12,200$200.2K0.04%+12,200New
Raymond James Financial Inc10,809$177.4K0.00%+10,809New
North Capital, Inc.10,000$164.1K0.13%+4,000+66.7%Added
BNP Paribas Arbitrage, SA10,000$164.1K0.00%+10,000New
Soltis Investment Advisors LLC10,000$164.1K0.01%+10,000New
Royal Bank of Canada7,000$115.0K0.00%+7,000New
Federation des caisses Desjardins du Quebec5,250$86.2K0.00%+4,050+337.5%Added
Anchor Investment Management, LLC2,100$34.5K0.00%00.0%Unchanged
CoreCap Advisors, LLC1,000$16.4K0.00%+1,000New
Group One Trading, L.P.576$9.45K0.00%+576New
Advisor Group Holdings, Inc.310$4.34K0.00%+110+55.0%Added
Steward Partners Investment Advisory, LLC200$3.28K0.00%+200New
Larson Financial Group LLC104$1.71K0.00%+104New
Koesten, Hirschmann & Crabtree, INC.50$8210.00%+50New
Redwood Park Advisors LLC44$7230.00%+44New
Wealthspire Advisors, LLC20$3290.00%+20New
Vivaldi Asset Management, LLC0$00.00%−1,051,124−100.0%Sold out
MMCAP International Inc. SPC0$00.00%−962,068−100.0%Sold out
Calamos Advisors LLC0$00.00%−500,000−100.0%Sold out
DLD Asset Management, LP0$00.00%−468,825−100.0%Sold out
Goldman Sachs Group Inc0$00.00%−435,071−100.0%Sold out
Commonwealth of Pennsylvania Public School Empls Retrmt Sys0$00.00%−405,962−100.0%Sold out
Rivernorth Capital Management, LLC0$00.00%−400,000−100.0%Sold out
Senator Investment Group LP0$00.00%−340,000−100.0%Sold out
Governors Lane LP0$00.00%−300,000−100.0%Sold out
Polar Asset Management Partners Inc.0$00.00%−257,307−100.0%Sold out
Scoggin Management LP0$00.00%−200,000−100.0%Sold out
Westchester Capital Management, LLC0$00.00%−199,691−100.0%Sold out
J. Goldman & Co LP0$00.00%−176,249−100.0%Sold out
Gritstone Asset Management LLC0$00.00%−173,847−100.0%Sold out
Mint Tower Capital Management B.V.0$00.00%−144,903−100.0%Sold out
Tenor Capital Management Co., L.P.0$00.00%−142,960−100.0%Sold out
Bulldog Investors, LLP0$00.00%−113,348−100.0%Sold out
Hidden Lake Asset Management LP0$00.00%−99,370−100.0%Sold out
Periscope Capital Inc.0$00.00%−85,000−100.0%Sold out
Wolverine Asset Management LLC0$00.00%−83,869−100.0%Sold out
Bluefin Capital Management, LLC0$00.00%−74,665−100.0%Sold out
Context Capital Management, LLC0$00.00%−54,800−100.0%Sold out
Shaolin Capital Management LLC0$00.00%−50,000−100.0%Sold out
Fifth Lane Capital, LP0$00.00%−45,000−100.0%Sold out
Yaupon Capital Management LP0$00.00%−35,139−100.0%Sold out
Toronto Dominion Bank0$00.00%−34,485−100.0%Sold out
Virtu Financial LLC0$00.00%−21,838−100.0%Sold out
Patriot Financial Group Insurance Agency, LLC0$00.00%−18,850−100.0%Sold out
Schonfeld Strategic Advisors LLC0$00.00%−11,394−100.0%Sold out
Gordian Capital Singapore Pte Ltd0$00.00%−3,000−100.0%Sold out
Tower Research Capital LLC (TRC)0$00.00%−105−100.0%Sold out
Citigroup Inc0$00.00%−50−100.0%Sold out