Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
346 institutional managers reported holding MIR for the quarter ended Mar 31, 2026. Reported positions total over 95% of shares outstanding; the top 10 hold 53%. 52 opened new positions; 63 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| BlackRock | 37.86M | 15.47% | $705.1M | trimmed -0.9% | 2021 Q4 |
| Vanguard Group | 30.46M | 12.45% | $567.3M | unchanged | 2021 Q4 |
| T. Rowe Price Investment Management, INC. | 14.63M | 5.98% | $272.4M | added +528.1% | 2023 Q1 |
| State Street | 9.43M | 3.85% | $175.6M | added +2.5% | 2021 Q4 |
| Cooperman Leon G (focused) | 8.38M | 3.43% | $156.1M | unchanged | 2021 Q4 |
| Goldman Sachs | 7.35M | 3.00% | $136.9M | added +40% | 2021 Q4 |
| FMR (Fidelity) | 6.55M | 2.68% | $122.0M | trimmed -22.1% | 2021 Q4 |
| Geode Capital | 5.94M | 2.43% | $110.6M | added +2.7% | 2021 Q4 |
| Millennium Management | 5.11M | 2.09% | $95.1M | opened | 2024 Q2 |
| Dimensional Fund Advisors | 4.69M | 1.92% | $87.4M | added +14.4% | 2023 Q2 |
| BNY Mellon | 4.54M | 1.85% | $84.5M | added +47.4% | 2021 Q4 |
| UBS | 4.27M | 1.75% | $79.6M | trimmed -19.3% | 2021 Q4 |
| Janus Henderson | 4.04M | 1.65% | $75.3M | trimmed -12% | 2021 Q4 |
| Swedbank Robur | 3.16M | 1.29% | $58.9M | trimmed -7% | 2021 Q4 |
| American Century Companies INC | 2.73M | 1.12% | $50.9M | added +6.9% | 2023 Q2 |
| Alyeska Investment Group | 2.70M | 1.10% | $50.3M | added +76.4% | 2021 Q4 |
| Loomis Sayles & CO L P | 2.67M | 1.09% | $49.7M | trimmed -6.2% | 2025 Q2 |
| Maverick Capital | 2.65M | 1.08% | $49.4M | opened | 2024 Q1 |
| Two Creeks Capital Management, LP (focused) | 2.45M | 1.00% | $45.6M | trimmed -16.2% | 2025 Q3 |
| Northern Trust | 2.37M | 0.97% | $44.1M | added +1.5% | 2021 Q4 |
| Invesco | 2.29M | 0.94% | $42.7M | trimmed -26% | 2022 Q1 |
| Morgan Stanley | 2.29M | 0.93% | $42.6M | added +9% | 2021 Q4 |
| Charles Schwab Investment Management | 2.28M | 0.93% | $42.4M | trimmed -2.9% | 2021 Q4 |
| TCW Group INC | 2.24M | 0.92% | $41.7M | trimmed -8.7% | 2025 Q2 |
| Franklin Resources | 2.00M | 0.82% | $37.2M | added +6.3% | 2025 Q2 |
| Royal Bank OF Canada | 1.96M | 0.80% | $36.5M | trimmed -8.7% | 2022 Q1 |
| Nuveen | 1.95M | 0.80% | $36.3M | trimmed -3.1% | 2022 Q2 |
| Conestoga Capital Advisors, LLC | 1.83M | 0.75% | $34.1M | trimmed -5.6% | 2025 Q3 |
| Citadel Advisors | 1.82M | 0.74% | $34.0M | added +12.5% | 2022 Q4 |
| Chescapmanager LLC (focused) | 1.66M | 0.68% | $30.9M | unchanged | 2024 Q1 |
| AllianceBernstein | 1.65M | 0.68% | $30.8M | added +415.9% | 2022 Q2 |
| MFS Investment Management | 1.59M | 0.65% | $29.6M | trimmed -56.6% | 2025 Q2 |
| Troluce Capital Advisors LLC (focused) | 1.50M | 0.61% | $27.9M | added +76.5% | 2025 Q2 |
| Nomura Asset Management International INC. | 1.49M | 0.61% | $27.8M | trimmed -7.7% | 2024 Q4 |
| Rockefeller Capital Management L.p. | 1.39M | 0.57% | $25.9M | added +22.3% | 2025 Q1 |
| Emerald Advisers, LLC | 1.38M | 0.56% | $25.7M | added +21.5% | 2024 Q4 |
| Stephens Investment Management Group LLC | 1.37M | 0.56% | $25.6M | added +69.7% | 2025 Q4 |
| Bank OF America CORP /DE/ | 1.36M | 0.55% | $25.2M | unchanged | 2021 Q4 |
| Davidson Kempner | 1.31M | 0.54% | $24.5M | added +41.6% | 2025 Q3 |
| Brown Advisory INC | 1.30M | 0.53% | $24.2M | trimmed -19.4% | 2024 Q4 |
| TimesSquare Capital Management, LLC | 1.29M | 0.53% | $24.1M | added +33.8% | 2025 Q3 |
| Ameriprise Financial INC | 1.29M | 0.53% | $24.0M | trimmed -44.8% | 2024 Q4 |
| Daiwa Securities Group INC. | 1.22M | 0.50% | $22.7M | added +2490.4% | 2025 Q2 |
| Bamco INC /NY/ | 1.21M | 0.50% | $22.6M | added +86.7% | 2025 Q3 |
| Principal Financial Group INC | 1.20M | 0.49% | $22.3M | trimmed -30% | 2021 Q4 |
| Voya Investment Management LLC | 1.17M | 0.48% | $21.8M | added +32.8% | 2022 Q2 |
| Schroder Investment Management Group | 1.14M | 0.46% | $21.2M | added +12.4% | 2024 Q4 |
| Segall Bryant & Hamill, LLC | 1.13M | 0.46% | $21.1M | trimmed -3.3% | 2024 Q2 |
| BNP Paribas Financial Markets | 1.12M | 0.46% | $20.8M | added +23% | 2024 Q4 |
| Congress Asset Management CO | 1.11M | 0.46% | $20.7M | opened | 2026 Q1 |
Largest 50 of 346 shown; the full ranked, searchable register is at boothcheck.com/holders/MIR. Related filers are grouped using the filings' own included-manager declarations. Historically, several managers opening new positions in the same quarter said almost nothing about the quarter that followed (59,118 cases since 2013). A filed record, not a forecast. Nothing here is investment advice.