Mirion Technologies, Inc. (MIR) Institutional Ownership

Ownership Summary

Mirion Technologies, Inc. (NYSE:MIR) showed up in the 13F filings of 353 institutional investors as of December 2025.

• They owned 100.1% of outstanding stock in December 2025, down from 107.4% the prior quarter.
• Their total shares held in MIR increased 3.86% from the prior quarter, while the number of investors in Mirion Technologies increased 58.3% year over year.
• During the quarter, 223 of these 353 funds increased positions in MIR, 93 reduced exposure, and 37 held steady.
• Combined, these investors held 255.79Mn shares in MIR for December 2025, up by 9.51Mn shares quarter on quarter, and up 58.14Mn shares year over year.
• As of December 31, 2025, BlackRock, Inc. held the largest stake in Mirion Technologies with 37.86Mn shares, accounting for 14.81% of total shares outstanding.
• The largest buyers of Mirion Technologies for the quarter ending December 2025 were VANGUARD PORTFOLIO MANAGEMENT LLC (17.91Mn), VANGUARD CAPITAL MANAGEMENT LLC (10.51Mn), MILLENNIUM MANAGEMENT LLC (5.11Mn), Janus Henderson Group Plc (3.49Mn), MAVERICK CAPITAL LTD (2.65Mn).
• The largest sales of MIR for the quarter ending December 2025 came from Swedbank AB (3.64Mn), Goldman Sachs Group Inc (3.15Mn), T. Rowe Price Investment Management, Inc. (2.81Mn), MASSACHUSETTS FINANCIAL SERVICES CO /MA/ (2.07Mn), FMR LLC (1.86Mn).
• According to Business Quant data, leading holders of MIR for December 2025 are BlackRock, Inc. (37.86Mn), VANGUARD PORTFOLIO MANAGEMENT LLC (17.91Mn), T. Rowe Price Investment Management, Inc. (14.63Mn), VANGUARD CAPITAL MANAGEMENT LLC (10.51Mn), State Street Corp (9.43Mn), COOPERMAN LEON G (8.38Mn), Janus Henderson Group Plc (8.09Mn), Goldman Sachs Group Inc (7.35Mn), FMR LLC (6.55Mn), GEODE CAPITAL MANAGEMENT, LLC (5.94Mn).