Mirion Technologies, Inc.
MIR- Exchange
- NYSE
- Industry
- Measuring & Controlling Devices, NEC
- SEC CIK
- 0001809987
In the last 90 days, Mirion Technologies, Inc. insiders filed 1 open-market purchase and 0 sales; 351 institutions reported holding it in 13F filings for Q2 2026, worth $4.70B in total; Maverick Capital is the only superinvestor holding it.
Holders of 5% or more of MIR
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Mirion Technologies, Inc., largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| BlackRock, Inc. | 13G/A | 14.80%35.7M shares | – | Oct 2, 20251 filing | Oct 2, 2025 | SEC |
| Vanguard Portfolio Management LLC | 13G | 7.40%18.1M shares | New | Apr 29, 20261 filing | Apr 29, 2026 | SEC |
| T. Rowe Price Investment Management, Inc. | 13G/A | 6.10%15.1M shares | – | Feb 17, 20261 filing | Feb 17, 2026 | SEC |
| Vanguard Capital Management LLC | 13G | 5.03%12.3M shares | New | Apr 30, 20261 filing | Apr 30, 2026 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
8 Schedule 13D and 13G filings on Mirion Technologies, Inc., newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Apr 30, 202611:30 AM ET | Vanguard Capital Management LLC | 13G | 5.03%12.3M shares | New | Mar 31, 2026 | SEC |
| Apr 29, 20262:17 PM ET | Vanguard Portfolio Management LLC | 13G | 7.40%18.1M shares | New | Mar 31, 2026 | SEC |
| Mar 27, 202610:49 AM ET | Vanguard Group Inc | 13G/A | 0.00%0 shares | −12.45 ppfrom 12.45%Below 5% | Mar 13, 2026 | SEC |
| Feb 17, 202610:28 AM ET | T. Rowe Price Investment Management, Inc. | 13G/A | 6.10%15.1M shares | – | Dec 31, 2025 | SEC |
| Jan 21, 20261:53 PM ET | Kuwait Investment Authority on Behalf of the Govt of Kuwait | 13G/A | 4.10%10.2M shares | –Below 5% | Jul 29, 2022 | SEC |
| Oct 31, 202511:02 AM ET | Vanguard Group Inc | 13G/A | 12.45%30.4M shares | – | Sep 30, 2025 | SEC |
| Oct 2, 20256:46 PM ET | BlackRock, Inc. | 13G/A | 14.80%35.7M shares | – | Sep 30, 2025 | SEC |
| Dec 18, 20248:24 PM ET | GSAM Holdings LLCand 2 others | 13D/A | 2.30%5.19M shares | –Below 5% | Dec 17, 2024 | SEC |
Form 144: proposed insider sales
Notices from officers, directors and other affiliates planning to sell Mirion Technologies, Inc. shares.
No Form 144 notices for Mirion Technologies, Inc. are on file.