Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
296 institutional managers reported holding MCY for the quarter ended Mar 31, 2026. Together they hold about 47% of shares outstanding; the top 10 hold 30%. 39 opened new positions; 56 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| BlackRock | 4.32M | 7.79% | $381.0M | trimmed -7.3% | ≤2013 |
| Vanguard Group | 3.16M | 5.70% | $278.8M | added +2.1% | ≤2013 |
| Rubric Capital Management LP | 2.15M | 3.89% | $190.1M | added +4.9% | 2025 Q1 |
| Dimensional Fund Advisors | 2.15M | 3.88% | $189.7M | added +2.2% | ≤2013 |
| State Street | 1.10M | 1.98% | $97.0M | trimmed -0.8% | ≤2013 |
| Renaissance Technologies | 823.6k | 1.49% | $72.7M | trimmed -6.6% | 2015 Q3 |
| American Century Companies INC | 813.3k | 1.47% | $71.8M | added +16.3% | 2020 Q3 |
| Geode Capital | 754.1k | 1.36% | $66.6M | added +19% | ≤2013 |
| DG Capital Management, LLC (focused) | 594.4k | 1.07% | $52.5M | trimmed -4.1% | 2025 Q1 |
| Arrowstreet Capital | 574.9k | 1.04% | $50.7M | unchanged | 2024 Q1 |
| Invesco | 572.7k | 1.03% | $50.5M | added +83.2% | ≤2013 |
| UBS | 390.7k | 0.70% | $34.5M | added +116.9% | ≤2013 |
| Morgan Stanley | 378.2k | 0.68% | $33.4M | trimmed -2.1% | ≤2013 |
| Charles Schwab Investment Management | 357.3k | 0.65% | $31.5M | trimmed -1.8% | ≤2013 |
| Jacobs Levy Equity Management, INC | 352.8k | 0.64% | $31.1M | trimmed -13.5% | 2019 Q3 |
| AQR Capital | 351.5k | 0.64% | $31.0M | added +3.1% | 2019 Q2 |
| Two Sigma | 289.0k | 0.52% | $25.5M | added +35% | 2022 Q3 |
| Northern Trust | 269.7k | 0.49% | $23.8M | added +3.9% | ≤2013 |
| Philosophy Capital Management LLC (focused) | 257.3k | 0.47% | $22.7M | unchanged | 2025 Q3 |
| Nuveen | 255.5k | 0.46% | $22.5M | trimmed -11.4% | 2019 Q2 |
| Westwood Holdings Group INC | 251.0k | 0.45% | $22.2M | trimmed -46% | 2025 Q1 |
| BNY Mellon | 243.5k | 0.44% | $21.5M | trimmed -2.2% | ≤2013 |
| BNP Paribas Financial Markets | 218.0k | 0.39% | $19.2M | added +34% | 2014 Q1 |
| Goldman Sachs | 193.1k | 0.35% | $17.0M | added +42.3% | ≤2013 |
| Park West Asset Management LLC (focused) | 193.0k | 0.35% | $17.0M | trimmed -41.4% | 2025 Q3 |
| Principal Financial Group INC | 178.1k | 0.32% | $15.7M | added +40.5% | ≤2013 |
| Algert Global LLC | 170.2k | 0.31% | $15.0M | added +142.6% | 2024 Q1 |
| Baird Financial Group, INC. | 145.6k | 0.26% | $12.9M | trimmed -9.6% | 2020 Q1 |
| SEI Investments CO | 141.6k | 0.26% | $12.5M | trimmed -3.3% | 2022 Q4 |
| Marshall Wace | 136.6k | 0.25% | $12.1M | opened | 2026 Q1 |
| Connor, Clark & Lunn Investment Management LTD. | 133.7k | 0.24% | $11.8M | trimmed -18.2% | 2022 Q2 |
| Qube Research & Technologies LTD | 119.1k | 0.21% | $10.5M | trimmed -35.4% | 2020 Q3 |
| Allianz Asset Management GmbH | 113.6k | 0.20% | $10.0M | opened | 2026 Q1 |
| Citadel Advisors | 110.3k | 0.20% | $9.7M | added +138.8% | 2024 Q4 |
| Raymond James Financial INC | 110.2k | 0.20% | $9.7M | added +13.1% | 2024 Q1 |
| Jane Street | 107.7k | 0.19% | $9.5M | added +25.6% | 2021 Q1 |
| Russell Investments Group, LTD. | 104.7k | 0.19% | $9.2M | trimmed -0.6% | 2016 Q4 |
| Public Sector Pension Investment Board | 95.1k | 0.17% | $8.4M | added +3.4% | 2022 Q3 |
| Voloridge Investment Management | 85.7k | 0.15% | $7.6M | added +45.2% | 2025 Q3 |
| Victory Capital Management INC | 85.3k | 0.15% | $7.5M | added +16.7% | 2023 Q4 |
| Ameriprise Financial INC | 82.4k | 0.15% | $7.3M | trimmed -8.2% | ≤2013 |
| Federated Hermes, INC. | 82.0k | 0.15% | $7.2M | added +5.2% | 2024 Q1 |
| Assenagon Asset Management S.a. | 80.1k | 0.14% | $7.1M | added +23% | 2022 Q4 |
| Aptus Capital Advisors, LLC | 79.7k | 0.14% | $7.0M | added +1.1% | 2025 Q3 |
| Bank OF America CORP /DE/ | 74.9k | 0.14% | $6.6M | added +85.7% | ≤2013 |
| Peak6 LLC | 74.3k | 0.13% | $6.6M | added +70.1% | 2025 Q3 |
| O'shaughnessy Asset Management, LLC | 74.0k | 0.13% | $6.5M | added +22.9% | 2024 Q4 |
| Legal & General Group PLC | 73.2k | 0.13% | $6.5M | trimmed -6.3% | ≤2013 |
| Rhumbline Advisers | 71.5k | 0.13% | $6.3M | added +0.6% | ≤2013 |
| Candriam S.c.a. | 66.8k | 0.12% | $5.9M | opened | 2026 Q1 |
Largest 50 of 296 shown; the full ranked, searchable register is at boothcheck.com/holders/MCY. 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.