Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
400 institutional managers reported holding MSM for the quarter ended Mar 31, 2026. Together they hold about 83% of shares outstanding; the top 10 hold 41%. 62 opened new positions; 74 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| BlackRock | 5.43M | 9.72% | $501.2M | added +1.7% | ≤2013 |
| Vanguard Group | 4.50M | 8.05% | $415.1M | added +6.5% | ≤2013 |
| American Century Companies INC | 2.61M | 4.67% | $241.1M | trimmed -7.7% | 2017 Q2 |
| Fuller & Thaler Asset Management, INC. | 1.79M | 3.19% | $164.7M | trimmed -0.6% | 2024 Q2 |
| First Trust Advisors LP | 1.77M | 3.17% | $163.6M | added +20.9% | 2014 Q1 |
| Boston Partners | 1.66M | 2.97% | $153.2M | trimmed -4.2% | 2024 Q3 |
| State Street | 1.41M | 2.52% | $130.2M | trimmed -12.3% | ≤2013 |
| Charles Schwab Investment Management | 1.39M | 2.49% | $128.5M | trimmed -18.4% | ≤2013 |
| Dimensional Fund Advisors | 1.36M | 2.43% | $125.2M | added +1.1% | ≤2013 |
| Invesco | 1.15M | 2.06% | $106.2M | trimmed -8.6% | ≤2013 |
| Geode Capital | 1.11M | 1.98% | $102.2M | added +5% | ≤2013 |
| Epoch Investment Partners, INC. | 976.6k | 1.75% | $90.1M | unchanged | 2020 Q4 |
| Victory Capital Management INC | 932.3k | 1.67% | $86.0M | trimmed -5.7% | 2019 Q3 |
| Millennium Management | 728.6k | 1.30% | $67.2M | added +71.2% | 2015 Q3 |
| Deprince Race & Zollo INC | 705.8k | 1.26% | $65.1M | added +43% | 2024 Q4 |
| Morgan Stanley | 616.2k | 1.10% | $56.9M | trimmed -8.1% | ≤2013 |
| Alberta Investment Management CORP | 602.0k | 1.08% | $55.5M | trimmed -2.8% | 2025 Q1 |
| NEW South Capital Management INC | 578.8k | 1.03% | $53.4M | trimmed -6.9% | ≤2013 |
| Mackenzie Financial CORP | 563.1k | 1.01% | $52.0M | trimmed -3.3% | 2024 Q4 |
| Point72 | 531.4k | 0.95% | $49.0M | added +1184.6% | 2025 Q3 |
| BNY Mellon | 487.1k | 0.87% | $44.9M | trimmed -1% | ≤2013 |
| Boston Trust Walden CORP | 486.5k | 0.87% | $44.9M | trimmed -11.9% | 2022 Q2 |
| UBS | 484.4k | 0.87% | $44.7M | trimmed -5.8% | ≤2013 |
| Allianz Asset Management GmbH | 472.0k | 0.84% | $43.5M | added +53.5% | 2022 Q3 |
| Quantinno Capital Management LP | 461.8k | 0.83% | $42.6M | trimmed -17.4% | 2021 Q4 |
| Pzena Investment Management | 444.6k | 0.80% | $41.0M | unchanged | 2019 Q4 |
| Northern Trust | 430.2k | 0.77% | $39.7M | added +9% | ≤2013 |
| FMR (Fidelity) | 414.0k | 0.74% | $38.2M | added +17.4% | 2016 Q1 |
| OLD Republic International CORP | 412.4k | 0.74% | $38.0M | trimmed -27% | 2019 Q3 |
| Citadel Advisors | 398.4k | 0.71% | $36.8M | added +141.2% | 2025 Q3 |
| Crawford Investment Counsel INC | 393.0k | 0.70% | $36.3M | added +3% | 2017 Q4 |
| Royce & Associates | 387.3k | 0.69% | $35.7M | trimmed -7.9% | 2019 Q4 |
| Brandes Investment Partners, LP | 372.5k | 0.67% | $34.4M | added +16.8% | 2023 Q4 |
| VAN Lanschot Kempen Investment Management N.v. | 358.7k | 0.64% | $33.1M | added +2.7% | 2023 Q2 |
| AllianceBernstein | 352.2k | 0.63% | $32.5M | trimmed -9.6% | ≤2013 |
| Balyasny Asset Management | 335.8k | 0.60% | $31.0M | opened | 2026 Q1 |
| FIL LTD | 326.7k | 0.58% | $30.1M | added +17.1% | 2023 Q1 |
| Bank OF America CORP /DE/ | 306.7k | 0.55% | $28.3M | trimmed -15.1% | ≤2013 |
| AQR Capital | 300.2k | 0.54% | $27.7M | added +3.3% | ≤2013 |
| Goldman Sachs | 300.0k | 0.54% | $27.7M | added +35.1% | ≤2013 |
| Medina Value Partners, LLC (focused) | 289.6k | 0.52% | $26.7M | opened | 2026 Q1 |
| Bragg Financial Advisors, INC | 282.3k | 0.51% | $26.0M | unchanged | 2020 Q1 |
| Gotham Asset Management | 242.0k | 0.43% | $22.3M | trimmed -4.4% | 2020 Q4 |
| Russell Investments Group, LTD. | 228.8k | 0.41% | $21.1M | added +11.9% | 2016 Q4 |
| Wellington Management | 209.3k | 0.37% | $19.3M | trimmed -3.7% | 2025 Q1 |
| Ameriprise Financial INC | 186.7k | 0.33% | $17.2M | trimmed -7.2% | ≤2013 |
| Janus Henderson | 185.6k | 0.33% | $17.1M | trimmed -52.8% | 2020 Q3 |
| Verition Fund Management | 171.4k | 0.31% | $15.8M | added +444.1% | 2021 Q4 |
| Lone Peak Global Investors LLC (focused) | 171.2k | 0.31% | $15.8M | added +3411% | 2024 Q2 |
| Schonfeld Strategic Advisors | 165.8k | 0.30% | $15.3M | trimmed -3.5% | 2024 Q1 |
Largest 50 of 400 shown; the full ranked, searchable register is at boothcheck.com/holders/MSM. 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.