Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in MIR held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 37.9M | $703.8M | -0.9% | 15.490% | 0.01% |
| 2 | VANGUARD PORTFOLIO MANAGEMENT LLC | 17.9M | $332.9M | — | 7.327% | 0.02% |
| 3 | VANGUARD CAPITAL MANAGEMENT LLC | 10.5M | $195.3M | — | 4.298% | 0.00% |
| 4 | STATE STREET CORP | 9.4M | $175.3M | +2.5% | 3.859% | 0.01% |
| 5 | COOPERMAN LEON G | 8.4M | $155.8M | 0.0% | 3.430% | 5.11% |
| 6 | GOLDMAN SACHS GROUP INC | 7.3M | $136.6M | +40.0% | 3.007% | 0.02% |
| 7 | FMR LLC | 6.6M | $121.8M | -22.1% | 2.681% | 0.01% |
| 8 | GEODE CAPITAL MANAGEMENT, LLC | 5.9M | $110.4M | +2.6% | 2.431% | 0.01% |
| 9 | DIMENSIONAL FUND ADVISORS LP | 4.7M | $87.2M | +14.4% | 1.921% | 0.02% |
| 10 | Bank of New York Mellon Corp | 4.5M | $84.3M | +47.4% | 1.856% | 0.02% |
| 11 | JANUS HENDERSON GROUP PLC | 4.0M | $75.2M | -12.0% | 1.654% | 0.04% |
| 12 | UBS Group AG | 3.8M | $70.0M | -22.4% | 1.541% | 0.01% |
| 13 | Swedbank AB | 3.2M | $58.7M | -7.0% | 1.293% | 0.06% |
| 14 | AMERICAN CENTURY COMPANIES INC | 2.7M | $50.8M | +6.9% | 1.118% | 0.03% |
| 15 | Alyeska Investment Group, L.P. | 2.7M | $50.2M | +76.4% | 1.105% | 0.14% |
| 16 | LOOMIS SAYLES & CO L P | 2.7M | $49.6M | -6.2% | 1.093% | 0.07% |
| 17 | MAVERICK CAPITAL LTD | 2.6M | $49.3M | — | 1.084% | 0.57% |
| 18 | Two Creeks Capital Management, LP | 2.4M | $45.5M | -16.2% | 1.002% | 4.81% |
| 19 | NORTHERN TRUST CORP | 2.4M | $44.0M | +1.5% | 0.968% | 0.01% |
| 20 | Invesco Ltd. | 2.3M | $42.7M | -26.0% | 0.939% | 0.01% |
| 21 | MORGAN STANLEY | 2.3M | $42.5M | +9.0% | 0.935% | 0.00% |
| 22 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 2.3M | $42.3M | -2.9% | 0.932% | 0.01% |
| 23 | TCW GROUP INC | 2.2M | $41.6M | -8.7% | 0.916% | 0.31% |
| 24 | ALLIANCEBERNSTEIN L.P. | 1.7M | $38.7M | +415.9% | 0.676% | 0.01% |
| 25 | CITADEL ADVISORS LLC | 2.0M | $38.1M | +3.1% | 0.838% | 0.02% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). “% of Fund” shows how much of that investor’s total 13F portfolio is invested in MIR — a direct measure of their conviction.
Filings activity in MIR during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings · Δ columns show change vs prior quarter
| Quarter | Inst. Holders | Δ Holders | Ownership % | Δ Ownership | Total 13F Value | Δ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 348 | 2.5% | 104.96% | 32.44 pp | $4.25B | 24% |
| Q4 2025 | 357 | +7.9% | 137.40% | +5.57 pp | $5.56B | +4.2% |
| Q3 2025 | 331 | +11% | 131.83% | +35.19 pp | $5.34B | +36% |
| Q2 2025 | 298 | +31% | 96.64% | +37.44 pp | $3.91B | +63% |
| Q1 2025 | 228 | +3.6% | 59.20% | 13.48 pp | $2.40B | 19% |
| Q4 2024 | 220 | +25% | 72.68% | +22.79 pp | $2.94B | +46% |
| Q3 2024 | 176 | +12% | 49.89% | +3.49 pp | $2.02B | +7.5% |
| Q2 2024 | 157 | — | 46.40% | — | $1.88B | — |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Δ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying MIR stock.
Based on Q1 2026 13F filings, institutional ownership of Mirion Technologies, Inc. stands at 105.0%, held across 348 reporting institutions.
BlackRock, Inc. is the largest reported institutional holder of MIR, with approximately 37,857,697 shares worth $0.70B as of Q1 2026.
Yes — 1 widely-followed marquee investor appear among the top 25 institutional holders of MIR, including CITADEL ADVISORS LLC.
Our composite Smart Money Score for MIR is 34 out of 100 (Bearish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
60 institutions opened new positions in MIR during Q1 2026, while 69 fully exited. 65 added to existing positions and 221 trimmed.
MIR institutional ownership fell by 32.44 percentage points quarter-over-quarter, with a net change of -9 holders.
The top 10 institutions account for 49.5% of all reported 13F value in MIR, and the top 25 account for 66.9%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Mirion Technologies, Inc. (MIR) Institutional Ownership