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IMSR

Terrestrial Energy
IMSR

45 hedge funds and large institutions have $213M invested in Terrestrial Energy in 2025 Q1 according to their latest regulatory filings, with 18 funds opening new positions, 3 increasing their positions, 15 reducing their positions, and 8 closing their positions.

New
Increased
Maintained
Reduced
Closed

125% more first-time investments, than exits

New positions opened: 18 | Existing positions closed: 8

32% more capital invested

Capital invested by funds: $162M → $213M (+$51.1M)

29% more funds holding

Funds holding: 35 → 45 (+10)

17.65% more ownership

Funds ownership: 70.36% → 88.01% (+18%)

80% less repeat investments, than reductions

Existing positions increased: 3 | Existing positions reduced: 15

Holders
45
Holders Change
+10
Holders Change %
+28.57%
% of All Funds
0.6%
Holding in Top 10
–
Holding in Top 10 Change
–
Holding in Top 10 Change %
–
% of All Funds
–
New
18
Increased
3
Reduced
15
Closed
8
Calls
–
Puts
–
Net Calls
–
Net Calls Change
–

Top Buyers

Rank Fund Capital Flow
1
LA
Linden Advisors
New York
+$20.3M
2
MF
Magnetar Financial
Illinois
+$19.9M
3
MI
MMCAP International
Cayman Islands
+$9.94M
4
ECA
Encompass Capital Advisors
New York
+$9.6M
5
Calamos Advisors
Calamos Advisors
Illinois
+$5.07M

Top Sellers

Rank Fund Capital Flow
1
KIM
Karpus Investment Management
New York
-$13M
2
WAM
Wolverine Asset Management
Illinois
-$5.19M
3
HCM
Highbridge Capital Management
New York
-$5.01M
4
FTCM
First Trust Capital Management
Illinois
-$3.46M
5
AA
AQR Arbitrage
Connecticut
-$2.79M
Name Holding Trade Value Shares
Change 		Change in
Stake
LA
1
Linden Advisors
New York
$21.1M +$20.3M +2,000,000 New
MF
2
Magnetar Financial
Illinois
$20.7M +$19.9M +1,959,198 New
PMAM
3
Picton Mahoney Asset Management
Ontario, Canada
$18.7M -$2.03M -200,000 -10%
FTCM
4
First Trust Capital Management
Illinois
$18.2M -$3.46M -341,046 -16%
LP
5
LMR Partners
United Kingdom
$14.9M -$896K -88,311 -6%
AA
6
AQR Arbitrage
Connecticut
$13.6M -$2.79M -275,159 -18%
MI
7
MMCAP International
Cayman Islands
$10.3M +$9.94M +980,000 New
D.E. Shaw & Co
8
D.E. Shaw & Co
New York
$10.3M +$507K +50,000 +5%
ECA
9
Encompass Capital Advisors
New York
$10M +$9.6M +946,165 New
WCMNY
10
Westchester Capital Management (New York)
New York
$7.09M – – –
Goldman Sachs
11
Goldman Sachs
New York
$6.51M -$216K -21,252 -3%
Calamos Advisors
12
Calamos Advisors
Illinois
$5.29M +$5.07M +500,000 New
Two Sigma Investments
13
Two Sigma Investments
New York
$5.26M – – –
COPPSERS
14
Commonwealth of Pennsylvania Public School Employees Retirement System
Pennsylvania
$4.27M +$4.12M +405,962 New
RCM
15
Rivernorth Capital Management
Florida
$4.21M – – –
WA
16
Whitebox Advisors
Minnesota
$4.21M – – –
PAMP
17
Polar Asset Management Partners
Ontario, Canada
$3.74M +$3.61M +355,845 New
CCM
18
Context Capital Management
California
$3.16M +$3.04M +300,000 New
WRBC
19
W.R. Berkley Corp
Connecticut
$3.13M – – –
BI
20
Bulldog Investors
New Jersey
$2.9M -$751K -73,995 -21%
WAM
21
Wolverine Asset Management
Illinois
$2.67M -$5.19M -511,965 -67%
DAM
22
DLD Asset Management
New York
$2.42M +$2.33M +229,636 New
GAM
23
Gritstone Asset Management
Maryland
$2.35M -$7.82K -771 -0.3%
Millennium Management
24
Millennium Management
New York
$2.1M -$2.54M -250,000 -56%
AC
25
Athos Capital
Hong Kong
$2.1M +$2.03M +200,000 New
1
2 3

IMSR Hedge Fund Activity: Q1 2025 in Review

45 of the 7,459 institutional investors tracked by Wall St. Rank reported a position in Terrestrial Energy (IMSR) for Q1 2025, worth a combined $213M — up 32% from $162M a quarter earlier.

Buyers outnumbered sellers: 18 funds opened new IMSR positions and 8 closed out — a net gain of 10 holders — while 3 added to existing stakes and 15 trimmed.

The largest buyer was Linden Advisors, opening a new position worth an estimated $20.3M. The largest seller was Karpus Investment Management, exiting entirely with an estimated $13M sold.

  • 45 institutional investors held Terrestrial Energy (IMSR) as of Q1 2025, up from 35 in Q4 2024.
  • Funds reported $213M of Terrestrial Energy stock for Q1 2025, up 32% quarter-over-quarter.
  • 18 funds opened new Terrestrial Energy positions in Q1 2025 and 8 closed out, a net change of +10 holders.
  • The largest Terrestrial Energy buyer in Q1 2025 was Linden Advisors, an estimated $20.3M added.
  • The largest Terrestrial Energy seller in Q1 2025 was Karpus Investment Management, an estimated $13M sold.

Based on aggregated 13F filings for Q1 2025.