MIRION TECHNOLOGIES INC (MIR) Institutional Shareholders
MIRION TECHNOLOGIES INC (MIR) is currently reported in institutional portfolios tracked by InsiderSet based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026. The institutional investors covered on this page collectively reported approximately $4.63B in MIR holdings during the latest filing period.
Blackrock, Inc. is currently the largest disclosed institutional shareholder of MIR tracked by InsiderSet, reporting ownership valued at approximately $686.04M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $603.01M, representing an estimated loss of -12.10% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 52% of the total disclosed MIR value among the investors covered in this analysis. Major shareholders include Blackrock, Inc., Vanguard Portfolio Management Llc, T. Rowe Price Investment Management, Inc., and several other long-term asset managers with concentrated positions in MIRION TECHNOLOGIES INC (MIR).
This page ranks the largest institutional MIR shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
335
Total Reported Value
$4.63B
Largest Holder
Blackrock, Inc.
Largest Position
$686.04M
Insider Transactions (90d)
2
Latest Filing Quarter
Q2 2026
New Institutional Positions
56
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Blackrock, Inc. | 0.01% | 38,262,307 | $686,043,174 | $603,013,958 | -$83,029,216 | -12.10% | |
| Vanguard Portfolio Management Llc | 0.01% | 18,179,850 | $325,964,711 | $286,514,436 | -$39,450,275 | -12.10% | |
| T. Rowe Price Investment Management, Inc. | 0.17% | 14,288,075 | $256,186,000 | $225,180,062 | -$31,005,938 | -12.10% | |
| Vanguard Capital Management Llc | 0.00% | 10,613,869 | $190,306,671 | $167,274,575 | -$23,032,096 | -12.10% | |
| Goldman Sachs Group Inc | 0.02% | 10,406,605 | $186,590,423 | $164,008,095 | -$22,582,328 | -12.10% | |
| State Street Corp | 0.01% | 9,923,609 | $177,930,309 | $156,396,078 | -$21,534,231 | -12.10% | |
| Alyeska Investment Group, L.P. | 0.44% | 9,534,955 | $170,961,743 | $150,270,891 | -$20,690,852 | -12.10% | |
| Cooperman Leon G | 4.24% | 8,383,441 | $150,315,097 | $132,123,030 | -$18,192,067 | -12.10% | |
| Fmr Llc | 0.01% | 7,329,386 | $131,415,889 | $115,511,123 | -$15,904,766 | -12.10% | |
| Congress Asset Management Co | 0.74% | 6,685,434 | $119,869,832 | $105,362,440 | -$14,507,392 | -12.10% | |
| Geode Capital Management, Llc | 0.01% | 6,280,048 | $112,622,147 | $98,973,556 | -$13,648,591 | -12.12% | |
| Maverick Capital Ltd | 0.85% | 5,245,039 | $94,043,549 | $82,661,815 | -$11,381,734 | -12.10% | |
| Dimensional Fund Advisors Lp | 0.02% | 4,859,755 | $87,125,072 | $76,589,739 | -$10,535,333 | -12.09% | |
| Janus Henderson Group Plc | 0.04% | 4,043,089 | $75,163,723 | $63,719,083 | -$11,444,640 | -15.23% | |
| Bamco Inc | 0.11% | 3,906,083 | $70,036,068 | $61,559,868 | -$8,476,200 | -12.10% | |
| Morgan Stanley | 0.00% | 3,896,754 | $69,868,819 | $61,412,843 | -$8,455,976 | -12.10% | |
| Neuberger Berman Group Llc | 0.04% | 3,199,539 | $57,367,734 | $50,424,735 | -$6,942,999 | -12.10% | |
| American Century Companies Inc | 0.03% | 3,176,241 | $56,950,035 | $50,057,558 | -$6,892,477 | -12.10% | |
| Invesco Ltd. | 0.00% | 2,769,589 | $49,658,731 | $43,648,723 | -$6,010,008 | -12.10% | |
| Ubs Group Ag | 0.01% | 2,686,713 | $48,172,763 | $42,342,597 | -$5,830,166 | -12.10% | |
| Northern Trust Corp | 0.01% | 2,586,059 | $46,368,038 | $40,756,290 | -$5,611,748 | -12.10% | |
| Jpmorgan Chase & Co | 0.00% | 2,606,507 | $45,694,266 | $41,078,550 | -$4,615,716 | -10.10% | |
| Swedbank Ab | 0.04% | 2,531,200 | $45,384,416 | $39,891,712 | -$5,492,704 | -12.10% | |
| Loomis Sayles & Co L P | 0.06% | 2,525,188 | $45,276,621 | $39,796,963 | -$5,479,658 | -12.10% | |
| Charles Schwab Investment Management Inc | 0.01% | 2,447,222 | $43,878,690 | $38,568,219 | -$5,310,471 | -12.10% | |
| Nuveen, Llc | 0.01% | 2,109,181 | $37,817,615 | $33,240,693 | -$4,576,922 | -12.10% | |
| Royal Bank Of Canada | 0.01% | 1,782,618 | $31,962,000 | $28,094,060 | -$3,867,940 | -12.10% | |
| Vanguard Fiduciary Trust Co | 0.01% | 1,723,956 | $30,910,531 | $27,169,547 | -$3,740,984 | -12.10% | |
| Stephens Investment Management Group Llc | 0.32% | 1,678,373 | $30,093,228 | $26,451,158 | -$3,642,070 | -12.10% | |
| Chescapmanager Llc | 3.86% | 1,659,137 | $29,748,326 | $26,147,999 | -$3,600,327 | -12.10% | |
| Davidson Kempner Capital Management Lp | 0.47% | 1,619,998 | $29,046,564 | $25,531,168 | -$3,515,396 | -12.10% | |
| Select Equity Group, L.P. | 0.15% | 1,576,023 | $28,258,092 | $24,838,122 | -$3,419,970 | -12.10% | |
| Schroder Investment Management Group | 0.02% | 1,594,840 | $27,845,906 | $25,134,678 | -$2,711,228 | -9.74% | |
| Troluce Capital Advisors Llc | 10.34% | 1,539,212 | $27,598,071 | $24,257,981 | -$3,340,090 | -12.10% | |
| Rockefeller Capital Management L.P. | 0.04% | 1,466,144 | $26,287,963 | $23,106,429 | -$3,181,534 | -12.10% | |
| Timessquare Capital Management, Llc | 0.37% | 1,400,642 | $25,113,511 | $22,074,118 | -$3,039,393 | -12.10% | |
| Bank Of New York Mellon Corp | 0.00% | 1,381,674 | $24,773,420 | $21,775,182 | -$2,998,238 | -12.10% | |
| Emerald Advisers, Llc | 0.58% | 1,364,780 | $24,470,505 | $21,508,933 | -$2,961,572 | -12.10% | |
| Conestoga Capital Advisors, Llc | 0.49% | 1,248,061 | $22,377,734 | $19,669,441 | -$2,708,293 | -12.10% | |
| Principal Financial Group Inc | 0.01% | 1,194,106 | $21,410,320 | $18,819,111 | -$2,591,209 | -12.10% | |
| Royal London Asset Management Ltd | 0.04% | 1,176,241 | $21,090,001 | $18,537,558 | -$2,552,443 | -12.10% | |
| Bank Of America Corp | 0.00% | 1,158,094 | $20,764,625 | $18,251,561 | -$2,513,064 | -12.10% | |
| Segall Bryant & Hamill, Llc | 0.24% | 1,131,124 | $20,281,053 | $17,826,514 | -$2,454,539 | -12.10% | |
| Wellington Management Group Llp | 0.00% | 1,098,987 | $19,704,837 | $17,320,035 | -$2,384,802 | -12.10% | |
| Clearbridge Investments, Llc | 0.02% | 1,096,729 | $19,664,354 | $17,284,449 | -$2,379,905 | -12.10% | |
| Ameriprise Financial Inc | 0.00% | 1,002,284 | $17,970,953 | $15,795,996 | -$2,174,957 | -12.10% | |
| Millennium Management Llc | 0.01% | 991,741 | $17,781,916 | $15,629,838 | -$2,152,078 | -12.10% | |
| Jennison Associates Llc | 0.01% | 887,170 | $15,906,960 | $13,981,799 | -$1,925,161 | -12.10% | |
| Emerald Mutual Fund Advisers Trust | 0.55% | 873,466 | $15,661,245 | $13,765,824 | -$1,895,421 | -12.10% | |
| Corsair Capital Management, L.P. | 1.96% | 867,670 | $15,557,323 | $13,674,479 | -$1,882,844 | -12.10% |
Frequently asked questions about MIR
Who owns the most MIR stock?
The largest holders of MIR are typically major institutional investors such as asset managers and hedge funds reporting on Form 13F. The table above ranks tracked superinvestors by reported position size using the latest available filings for MIRION TECHNOLOGIES INC (MIR).
Is MIR widely held by superinvestors?
Many widely followed stocks like MIR appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly MIR is represented among the institutional managers we track.
What do “Current Estimated Value”, “Gain/loss Since Filing”, and “Estimated Portfolio Performance” mean?
Current Estimated Value is reported share quantity from the latest 13F times our most recent split-adjusted U.S. session close. Gain/loss Since Filing is that estimate minus the reported 13F dollar value; Estimated Portfolio Performance is that difference as a percent of the reported value. Green means the estimate is above the filing value; red means below (not purchase cost). If many filers share the same implied filing price per share, the performance % may match across rows. These are not official fund marks or live quotes.