Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
3,701 institutional managers reported holding MRK for the quarter ended Mar 31, 2026. Together they hold about 76% of shares outstanding; the top 10 hold 39%. 302 opened new positions; 201 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| Vanguard Group | 254.51M | 10.30% | $30.60B | unchanged | ≤2013 |
| BlackRock | 225.83M | 9.14% | $27.15B | added +3.1% | ≤2013 |
| State Street | 119.33M | 4.83% | $14.35B | trimmed -0.6% | ≤2013 |
| Wellington Management | 84.31M | 3.41% | $10.14B | trimmed -2.5% | ≤2013 |
| Geode Capital | 59.56M | 2.41% | $7.16B | trimmed -0.8% | ≤2013 |
| Charles Schwab Investment Management | 49.77M | 2.01% | $5.98B | added +2.5% | ≤2013 |
| Morgan Stanley | 47.63M | 1.93% | $5.73B | added +6% | ≤2013 |
| FMR (Fidelity) | 44.52M | 1.80% | $5.35B | added +9% | ≤2013 |
| UBS | 34.35M | 1.39% | $4.13B | trimmed -11% | ≤2013 |
| Bank OF America CORP /DE/ | 30.77M | 1.25% | $3.70B | added +10.5% | ≤2013 |
| Northern Trust | 27.09M | 1.10% | $3.26B | trimmed -0.5% | ≤2013 |
| Fisher Investments | 26.44M | 1.07% | $3.18B | added +6.3% | ≤2013 |
| T. Rowe Price | 23.04M | 0.93% | $2.77B | added +22.9% | ≤2013 |
| Invesco | 21.86M | 0.88% | $2.63B | added +6.4% | ≤2013 |
| Goldman Sachs | 20.13M | 0.81% | $2.42B | added +4.1% | ≤2013 |
| Legal & General Group PLC | 19.54M | 0.79% | $2.35B | trimmed -1.2% | ≤2013 |
| BNY Mellon | 18.71M | 0.76% | $2.25B | trimmed -2.4% | ≤2013 |
| Franklin Resources | 16.27M | 0.66% | $1.96B | added +1.3% | ≤2013 |
| Ameriprise Financial INC | 16.26M | 0.66% | $1.96B | added +1.8% | ≤2013 |
| Dimensional Fund Advisors | 15.46M | 0.63% | $1.86B | added +23.8% | ≤2013 |
| State Farm Mutual Automobile Insurance CO | 13.79M | 0.56% | $1.66B | unchanged | ≤2013 |
| Amundi | 13.76M | 0.56% | $1.65B | added +2.8% | ≤2013 |
| Royal Bank OF Canada | 13.20M | 0.53% | $1.59B | unchanged | ≤2013 |
| Deutsche Bank AG\ | 12.54M | 0.51% | $1.51B | trimmed -1.9% | ≤2013 |
| Harris Associates (Oakmark) | 12.37M | 0.50% | $1.49B | trimmed -12.2% | 2024 Q3 |
| Wells Fargo & COMPANY/MN | 11.45M | 0.46% | $1.38B | added +3.6% | ≤2013 |
| AllianceBernstein | 11.30M | 0.46% | $1.36B | added +30.9% | ≤2013 |
| Nuveen | 10.10M | 0.41% | $1.21B | added +45.2% | ≤2013 |
| AQR Capital | 8.63M | 0.35% | $1.04B | trimmed -23.3% | ≤2013 |
| Nordea Investment Management AB | 8.53M | 0.34% | $1.03B | trimmed -19.3% | ≤2013 |
| Stifel Financial CORP | 8.29M | 0.34% | $996.9M | trimmed -3% | ≤2013 |
| Barrow Hanley Mewhinney & Strauss LLC | 7.92M | 0.32% | $951.9M | added +1.6% | ≤2013 |
| Hsbc Holdings PLC | 7.63M | 0.31% | $917.8M | trimmed -5.5% | ≤2013 |
| Barclays PLC | 7.56M | 0.31% | $908.6M | added +58.3% | ≤2013 |
| PNC Financial Services Group, INC. | 7.53M | 0.30% | $905.3M | trimmed -1.2% | ≤2013 |
| CalPERS | 7.38M | 0.30% | $887.6M | trimmed -13.8% | ≤2013 |
| Mitsubishi UFJ Asset Management CO., LTD. | 7.37M | 0.30% | $885.9M | added +4.7% | ≤2013 |
| Swiss National Bank | 7.28M | 0.29% | $875.7M | added +6.4% | ≤2013 |
| Swedbank Robur | 7.09M | 0.29% | $852.6M | trimmed -7.3% | 2021 Q1 |
| Grantham, Mayo, Van Otterloo & CO. LLC | 7.01M | 0.28% | $843.2M | added +2.1% | 2016 Q3 |
| Aristotle Capital Management, LLC | 6.89M | 0.28% | $828.9M | trimmed -5.3% | 2022 Q3 |
| Raymond James Financial INC | 6.59M | 0.27% | $791.7M | trimmed -5% | ≤2013 |
| Sumitomo Mitsui Trust Group, INC. | 6.27M | 0.25% | $753.7M | trimmed -10.1% | ≤2013 |
| Jennison Associates LLC | 6.25M | 0.25% | $751.3M | added +12.4% | 2025 Q4 |
| National Pension Service | 5.76M | 0.23% | $692.7M | unchanged | 2014 Q3 |
| American Century Companies INC | 5.55M | 0.22% | $667.0M | added +3.3% | ≤2013 |
| DekaBank Deutsche Girozentrale | 5.43M | 0.22% | $652.6M | unchanged | ≤2013 |
| Voya Investment Management LLC | 5.16M | 0.21% | $620.3M | added +72.7% | ≤2013 |
| LSV Asset Management | 5.09M | 0.21% | $611.8M | trimmed -1.7% | ≤2013 |
| Bank OF Montreal /CAN/ | 4.83M | 0.20% | $580.8M | trimmed -10.1% | ≤2013 |
Largest 50 of 3,701 shown; the full ranked, searchable register is at boothcheck.com/holders/MRK. 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.