Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
806 institutional managers reported holding MAS for the quarter ended Mar 31, 2026. Together they hold about 94% of shares outstanding; the top 10 hold 44%. 87 opened new positions; 101 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| Vanguard Group | 27.38M | 13.42% | $1.65B | trimmed -1.7% | ≤2013 |
| BlackRock | 15.62M | 7.66% | $943.0M | trimmed -5.3% | ≤2013 |
| State Street | 9.96M | 4.88% | $601.3M | trimmed -2.7% | ≤2013 |
| Harris Associates (Oakmark) | 8.60M | 4.21% | $519.0M | trimmed -25.3% | 2022 Q2 |
| VAN ECK Associates CORP | 5.84M | 2.86% | $352.7M | added +73.1% | 2020 Q4 |
| Geode Capital | 5.35M | 2.63% | $323.3M | added +0.7% | ≤2013 |
| Nordea Investment Management AB | 4.50M | 2.21% | $271.8M | added +3% | ≤2013 |
| Boston Partners | 4.49M | 2.20% | $271.2M | trimmed -21.6% | ≤2013 |
| MFS Investment Management | 4.32M | 2.12% | $261.0M | trimmed -3.5% | 2019 Q2 |
| Wellington Management | 4.24M | 2.08% | $255.7M | trimmed -12.2% | 2025 Q3 |
| Invesco | 3.79M | 1.86% | $228.7M | added +11.2% | ≤2013 |
| Northern Trust | 3.28M | 1.61% | $198.1M | trimmed -3.5% | ≤2013 |
| Beutel, Goodman & CO LTD. | 3.17M | 1.55% | $191.2M | trimmed -4.4% | 2022 Q2 |
| Morgan Stanley | 2.76M | 1.35% | $166.5M | unchanged | ≤2013 |
| Holocene Advisors | 2.62M | 1.28% | $158.2M | trimmed -36.4% | 2022 Q2 |
| Pictet Asset Management Holding SA | 2.50M | 1.23% | $150.9M | trimmed -24.3% | ≤2013 |
| Nuveen | 2.41M | 1.18% | $145.4M | added +35.6% | ≤2013 |
| Impax Asset Management Group plc | 2.38M | 1.17% | $143.5M | trimmed -12.3% | 2022 Q1 |
| Fiduciary Management INC /WI/ | 2.37M | 1.16% | $143.0M | trimmed -10.2% | 2018 Q2 |
| Jacobs Levy Equity Management, INC | 2.35M | 1.15% | $141.8M | trimmed -9.4% | 2023 Q4 |
| UBS | 2.18M | 1.07% | $131.8M | trimmed -5.5% | ≤2013 |
| Earnest Partners LLC | 2.18M | 1.07% | $131.6M | trimmed -1.9% | 2013 Q4 |
| Amundi | 2.15M | 1.05% | $130.0M | added +17.5% | 2016 Q3 |
| Deutsche Bank AG\ | 2.07M | 1.02% | $125.2M | trimmed -12.2% | 2013 Q3 |
| Bank OF America CORP /DE/ | 2.01M | 0.98% | $121.1M | trimmed -1.1% | ≤2013 |
| Charles Schwab Investment Management | 1.97M | 0.97% | $119.2M | added +1.4% | ≤2013 |
| Goldman Sachs | 1.97M | 0.97% | $119.0M | added +7.4% | ≤2013 |
| BNY Mellon | 1.96M | 0.96% | $118.4M | added +8.8% | ≤2013 |
| American Century Companies INC | 1.86M | 0.91% | $112.6M | added +23.5% | 2018 Q3 |
| Capital Group (American Funds) | 1.63M | 0.80% | $98.1M | unchanged | ≤2013 |
| Schroder Investment Management Group | 1.58M | 0.78% | $95.7M | trimmed -2.3% | 2018 Q3 |
| Quantinno Capital Management LP | 1.54M | 0.76% | $93.1M | added +52.3% | 2023 Q3 |
| First Trust Advisors LP | 1.24M | 0.61% | $75.0M | added +10% | 2019 Q1 |
| Dimensional Fund Advisors | 1.23M | 0.60% | $74.2M | added +3% | ≤2013 |
| Renaissance Technologies | 1.13M | 0.56% | $68.5M | added +27.1% | 2014 Q4 |
| Empower Advisory Group, LLC | 1.13M | 0.56% | $68.4M | trimmed -0.6% | 2023 Q1 |
| Arrowstreet Capital | 1.07M | 0.53% | $64.7M | added +828.7% | 2023 Q4 |
| Envestnet Asset Management INC | 1.06M | 0.52% | $64.3M | added +8.3% | ≤2013 |
| AQR Capital | 1.00M | 0.49% | $60.7M | added +27% | ≤2013 |
| Mitsubishi UFJ Asset Management CO., LTD. | 978.6k | 0.48% | $59.1M | added +6.6% | ≤2013 |
| Caisse de depot et placement du Quebec | 848.1k | 0.42% | $51.2M | added +55.8% | 2024 Q2 |
| Squarepoint Ops LLC | 843.5k | 0.41% | $50.9M | added +15139.5% | 2020 Q3 |
| Confluence Investment Management LLC | 828.6k | 0.41% | $50.0M | trimmed -4% | 2022 Q3 |
| Eurizon Capital SGR S.p.A. | 810.8k | 0.40% | $49.0M | added +246.1% | 2025 Q4 |
| Legal & General Group PLC | 774.1k | 0.38% | $46.7M | trimmed -29.8% | ≤2013 |
| Fuller & Thaler Asset Management, INC. | 718.7k | 0.35% | $43.4M | added +22.4% | 2021 Q4 |
| Boston Trust Walden CORP | 713.6k | 0.35% | $43.1M | added +37.7% | 2019 Q1 |
| Vaughan Nelson Investment Management, L.p. | 635.3k | 0.31% | $38.4M | added +2.3% | 2025 Q3 |
| Citigroup INC | 614.1k | 0.30% | $37.1M | added +23.4% | ≤2013 |
| Swiss National Bank | 609.6k | 0.30% | $36.8M | added +6% | ≤2013 |
Largest 50 of 806 shown; the full ranked, searchable register is at boothcheck.com/holders/MAS. 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.