Terrestrial EnergyIMSR
13F holders, Q1 2025 (March 31)At the end of Q1 2025, 45 institutions reported holding Terrestrial Energy Inc. (IMSR) in their 13F filings, up 10 from Q4 2024. 13 opened new positions and 8 sold out. The largest holders were Linden Advisors LP ($21.1M), Magnetar Financial LLC ($20.7M) and Picton Mahoney Asset Management ($18.7M). 2 famous investors held it, including David E. Shaw (0.0% of D. E. Shaw & Co.'s portfolio) and Israel Englander (0.0% of Millennium Management's portfolio).
- Company
- Terrestrial Energy Inc.
- Filed as
- HCM II ACQUISITION CORP (Q1 2025)
- CUSIP
- G43658106
- Latest filing quarter
- Q3 2025
History
Number of 13F holders
Total Exit/New Position Q4 2024 → Q1 2025
| Institutions | Total Value | |
|---|---|---|
| New Positions | 13 | $43.6M |
| Exits | 8 | $22.4M |
All 13F filers, Q4 2024 → Q1 2025: 4,289,353 shares bought and 4,320,301 shares sold, net −30,948 shares. Counts holders who added, trimmed, opened or closed a position; split-adjusted.
Ownership 45 holders
| Linden Advisors LP | 4.62% | New | 2,000,000 | $21.1M |
| Magnetar Financial LLC | 0.30% | No change | 1,959,198 | $20.7M |
| Picton Mahoney Asset Management | 0.64% | Reduce -10.1% | 1,780,000 | $18.7M |
| First Trust Capital Management L.P. | 1.31% | Reduce -16.5% | 1,728,952 | $18.2M |
| LMR Partners LLP | 0.41% | Reduce -5.9% | 1,411,689 | $14.9M |
| AQR Arbitrage LLC | 0.59% | Reduce -17.6% | 1,288,674 | $13.6M |
| MMCAP International Inc. SPC | 1.78% | No change | 980,000 | $10.3M |
| D. E. Shaw & Co. | 0.01% | Add +5.4% | 970,000 | $10.3M |
| Encompass Capital Advisors LLC | 0.38% | New | 946,165 | $10.0M |
| Westchester Capital Management, LLC | 0.42% | No change | 670,481 | $7.1M |
| Goldman Sachs Group Inc. | 0.00% | Reduce -3.3% | 618,772 | $6.5M |
| Calamos Advisors LLC | 0.04% | No change | 500,000 | $5.3M |
| Two Sigma Investments, LP | 0.01% | No change | 500,000 | $5.3M |
| Commonwealth of Pennsylvania Public School Empls Retrmt SYS | 0.03% | New | 405,962 | $4.3M |
| Whitebox Advisors LLC | 0.36% | No change | 400,000 | $4.2M |
| Rivernorth Capital Management, LLC | 0.22% | No change | 400,000 | $4.2M |
| Polar Asset Management Partners Inc. | 0.17% | Add +18.6% | 355,845 | $3.7M |
| Context Capital Management, LLC | 4.23% | Reduce -14.3% | 300,000 | $3.2M |
| Berkley W R Corp. | 0.23% | No change | 297,240 | $3.1M |
| Bulldog Investors, LLP | 0.79% | Reduce -21.1% | 275,903 | $2.9M |
| Wolverine Asset Management LLC | 0.20% | Reduce -66.8% | 254,029 | $2.7M |
| DLD Asset Management, LP | 2.08% | New | 229,636 | $2.4M |
| Gritstone Asset Management LLC | 2.52% | Reduce -0.3% | 223,847 | $2.4M |
| Athos Capital Ltd | 2.67% | New | 200,000 | $2.1M |
| Millennium Management | 0.00% | Reduce -55.6% | 200,000 | $2.1M |
| Verition Fund Management LLC | 0.01% | Reduce -10.2% | 182,612 | $1.9M |
| TENOR CAPITAL MANAGEMENT Co., L.P. | 0.54% | No change | 175,000 | $1.8M |
| Periscope Capital Inc. | 1.02% | Reduce -22.5% | 155,000 | $1.6M |
| Mint Tower Capital Management B.V. | 1.16% | No change | 144,903 | $1.5M |
| Deltec Asset Management LLC | 0.26% | Reduce -23.3% | 115,000 | $1.2M |
| HRT Financial LP | 0.01% | New | 99,320 | $1.1M |
| Toronto Dominion Bank | 0.00% | Add +138.1% | 75,445 | $798K |
| Balyasny Asset Management L.P. | 0.00% | New | 65,000 | $687K |
| Decagon Asset Management LLP | 0.54% | New | 56,178 | $591K |
| Schonfeld Strategic Advisors LLC | 0.00% | Reduce -40.0% | 45,009 | $473K |
| Susquehanna International Group, LLP | 0.00% | New | 40,291 | $426K |
| Glazer Capital, LLC | 0.02% | New | 36,831 | $387K |
| Tuttle Capital Management, LLC | 1.62% | No change | 35,000 | $368K |
| UBS Group AG | 0.00% | Add +86.8% | 31,050 | $327K |
| PenderFund Capital Management Ltd. | 0.11% | No change | 30,000 | $296K |
| Mizuho Securities USA LLC | 0.01% | New | 25,837 | $271K |
| Morgan Stanley | 0.00% | New | 20,000 | $210K |
| Virtu Financial LLC | 0.01% | Reduce -90.7% | 13,540 | $143K |
| Clear Street LLC | 0.00% | Reduce -98.0% | 165 | $2K |
| FNY Investment Advisers, LLC | 0.00% | New | 100 | $1K |
"% of holder's portfolio" is IMSR's weight in each manager's 13F, not the share of Terrestrial Energy Inc. the manager owns.