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Mirion Technologies

365 hedge funds and large institutions have $5.91B invested in Mirion Technologies in 2025 Q4 according to their latest regulatory filings, with 82 funds opening new positions, 147 increasing their positions, 94 reducing their positions, and 54 closing their positions.

New
Increased
Maintained
Reduced
Closed

1,114% more call options, than puts

Call options by funds: $206M | Put options by funds: $16.9M

56% more repeat investments, than reductions

Existing positions increased: 147 | Existing positions reduced: 94

52% more first-time investments, than exits

New positions opened: 82 | Existing positions closed: 54

7% more funds holding

Funds holding: 341365 (+24)

0% more funds holding in top 10

Funds holding in top 10: 66 (0)

0% less capital invested

Capital invested by funds: $5.93B → $5.91B (-$23.7M)

10.14% less ownership

Funds ownership: 111.91%101.77% (-10%)

Holders
365
Holders Change
+24
Holders Change %
+7.04%
% of All Funds
4.44%
Holding in Top 10
6
Holding in Top 10 Change
Holding in Top 10 Change %
% of All Funds
0.07%
New
82
Increased
147
Reduced
94
Closed
54
Calls
$206M
Puts
$16.9M
Net Calls
+$189M
Net Calls Change
+$131M
Name Holding Trade Value Shares
Change
Change in
Stake
KI
101
Keystone Investors
Singapore
$7.26M -$14.3M -571,706 -65%
EIM
102
Essex Investment Management
Massachusetts
$7.1M -$178K -7,148 -2%
RA
103
Royce & Associates
New York
$6.88M +$3.54M +141,835 +93%
ETC
104
Exchange Traded Concepts
Oklahoma
$6.88M +$1.02M +40,709 +16%
TAF
105
Tredje AP-fonden
Sweden
$6.58M +$7M +280,788 New
EF
106
Empowered Funds
Pennsylvania
$6.53M -$305K -12,244 -4%
AQR Capital Management
107
AQR Capital Management
Connecticut
$6.5M -$365K -14,619 -5%
LCM
108
Legato Capital Management
California
$6.48M +$2.21M +88,464 +47%
MAM
109
Montanaro Asset Management
United Kingdom
$5.98M +$2.09M +83,800 +49%
GCM
110
Ghisallo Capital Management
Massachusetts
$5.86M -$13.1M -524,900 -68%
Wellington Management Group
111
Wellington Management Group
Massachusetts
$5.83M +$6.2M +248,775 New
Envestnet Asset Management
112
Envestnet Asset Management
Illinois
$5.8M +$475K +19,050 +8%
Walleye Capital
113
Walleye Capital
New York
$5.58M -$5.39M -216,292 -48%
Prudential Financial
114
Prudential Financial
New Jersey
$5.42M -$258K -10,360 -4%
RS
115
Robeco Schweiz
Switzerland
$5.39M
State of Wisconsin Investment Board
116
State of Wisconsin Investment Board
Wisconsin
$5.31M +$2.24M +89,775 +66%
TIM
117
Thornburg Investment Management
New Mexico
$5.3M +$5.64M +226,209 New
California State Teachers Retirement System (CalSTRS)
118
California State Teachers Retirement System (CalSTRS)
California
$5.25M +$658K +26,376 +13%
Comerica Bank
119
Comerica Bank
Texas
$5.22M +$1.08M +43,450 +24%
MP
120
Munro Partners
Australia
$5.22M +$569K +22,810 +11%
ZCI
121
Zevenbergen Capital Investments
Washington
$5.18M -$254K -10,200 -4%
RHJA
122
Rice Hall James & Associates
California
$4.68M -$578K -23,179 -10%
Bessemer Group
123
Bessemer Group
New Jersey
$4.62M +$4.9M +196,666 +28,964%
EI
124
EAM Investors
California
$4.53M +$1.16M +46,593 +32%
New York State Common Retirement Fund
125
New York State Common Retirement Fund
New York
$4.11M +$145K +5,800 +3%

MIR Hedge Fund Activity: Q4 2025 in Review

365 of the 8,223 institutional investors tracked by Wall St. Rank reported a position in Mirion Technologies (MIR) for Q4 2025, worth a combined $5.91B — down 0.4% from $5.93B a quarter earlier.

Buyers outnumbered sellers: 82 funds opened new MIR positions and 54 closed out — a net gain of 28 holders — while 147 added to existing stakes and 94 trimmed.

The largest buyer was TCW Group, opening a new position worth an estimated $61.2M. The largest seller was T. Rowe Price Investment Management, cutting an estimated $161M.

  • 365 institutional investors held Mirion Technologies (MIR) as of Q4 2025, up from 341 in Q3 2025.
  • Funds reported $5.91B of Mirion Technologies stock for Q4 2025, down 0.4% quarter-over-quarter.
  • 82 funds opened new Mirion Technologies positions in Q4 2025 and 54 closed out, a net change of +28 holders.
  • The largest Mirion Technologies buyer in Q4 2025 was TCW Group, an estimated $61.2M added.
  • The largest Mirion Technologies seller in Q4 2025 was T. Rowe Price Investment Management, an estimated $161M sold.

Based on aggregated 13F filings for Q4 2025.