MRK
Merck & Co., Inc. · Healthcare · Drug Manufacturers - General
Momentum inputs (comparable managers):
holder breadth -4.3% ·
share flow +3.1% ·
net new positions -4.5%
· formula
Concentrated accumulation: rising shares among fewer holders
All ownership figures: tracked 13F managers only, common-stock positions, reporting period Q1 2025
| Quarter | Holders | Δ | Shares | Reported value | New | Exits |
|---|---|---|---|---|---|---|
| Q3 2026 | 6 | 0 | 6.46M | $911.98M | n/a | n/a |
| Q2 2026 | 183 | 0 | 1.60B | $205.64B | +4 | −3 |
| Q1 2026 | 185 | +1 | 1.56B | $186.85B | +3 | −3 |
| Q4 2025 | 183 | 0 | 1.68B | $176.48B | +1 | n/a |
| Q3 2025 | 27 | 0 | 972.48M | $81.66B | +1 | −2 |
| Q2 2025 | 25 | 0 | 887.01M | $70.29B | +1 | −1 |
| Q1 2025 | 22 | -1 | 386.62M | $34.78B | n/a | −1 |
| Q4 2024 | 23 | -1 | 374.82M | $37.37B | n/a | −1 |
| Q3 2024 | 23 | +1 | 256.79M | $29.14B | +1 | n/a |
| Q2 2024 | 22 | n/a | 256.16M | $31.70B | n/a | n/a |
| # | Manager | Shares | Δ shares | Value | Their weight | Held | ||
|---|---|---|---|---|---|---|---|---|
| 1 | State Street Global Advisors ✦ (passive) | 120.53M | -0.3% | $10.91B | 0.5% | ▼ Trim | 2 | SEC ↗ |
| 2 | Wellington Management ✦ | 81.67M | +1.1% | $7.33B | 1.4% | ▲ Add | 4 | SEC ↗ ×9 |
| 3 | Geode Capital Management ✦ (passive) | 59.66M | -2.5% | $5.34B | 0.4% | ▼ Trim | 4 | SEC ↗ ×2 |
| 4 | Norges Bank ✦ (passive) | 38.23M | +9.3% | $3.43B | 0.5% | ▲ Add | 4 | SEC ↗ |
| 5 | Fisher Asset Management ✦ | 24.45M | +51.7% | $2.19B | 0.9% | ▲ Add | 4 | SEC ↗ |
| 6 | Arrowstreet Capital ✦ | 14.36M | +121.9% | $1.29B | 1.0% | ▲ Add | 4 | SEC ↗ |
| 7 | T. Rowe Price ✦ | 11.77M | -6.0% | $1.06B | 0.1% | ▼ Trim | 4 | SEC ↗ ×2 |
| 8 | D. E. Shaw & Co. ✦ | 9.31M | +46.1% | $835.82M | 1.1% | ▲ Add | 4 | SEC ↗ ×2 |
| 9 | AQR Capital Management ✦ | 7.76M | +44.3% | $691.07M | 0.7% | ▲ Add | 4 | SEC ↗ ×7 |
| 10 | Harris Associates (Oakmark) ✦ | 7.47M | +19.6% | $670.45M | 1.1% | ▲ Add | 3 | SEC ↗ ×2 |
| 11 | Millennium Management ✦ | 3.52M | -1.6% | $316.37M | 0.3% | ▼ Trim | 4 | SEC ↗ |
| 12 | Two Sigma Investments ✦ | 2.20M | +14.1% | $197.53M | 0.4% | ▲ Add | 4 | SEC ↗ |
| 13 | Citadel Advisors ✦ | 2.05M | -61.2% | $183.89M | 0.2% | ▼ Trim | 4 | SEC ↗ ×2 |
| 14 | Adage Capital Partners ✦ | 2.03M | +35.5% | $181.90M | 0.3% | ▲ Add | 4 | SEC ↗ |
| 15 | Bridgewater Associates ✦ | 534.87K | -62.8% | $48.01M | 0.2% | ▼ Trim | 4 | SEC ↗ |
| 16 | Gotham Asset Management ✦ | 395.42K | -7.0% | $35.49M | 0.3% | ▼ Trim | 4 | SEC ↗ |
| 17 | Renaissance Technologies ✦ | 221.69K | -84.0% | $19.90M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 18 | Fairfax Financial ✦ | 172.90K | 0.0% | $15.51M | 0.8% | Held | 4 | SEC ↗ |
| 19 | Dodge & Cox ✦ | 157.07K | -0.2% | $14.10M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 20 | GAMCO Investors ✦ | 72.63K | -8.2% | $6.52M | 0.1% | ▼ Trim | 4 | SEC ↗ |
| 21 | PRIMECAP Management ✦ | 57.50K | -4.8% | $5.16M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 22 | Marshall Wace ✦ | 7.61K | +2198.2% | $682,804 | 0.0% | ▲ Add | 4 | SEC ↗ ×2 |
“Their weight” = the position's share of that manager's reported 13F equity value: the conviction measure. ✦ = curated manager.
New buyers
| No new tracked buyers this quarter. |
Exited
| Capital World Investors | $786.58M | was 0.1% |
Full-market context: across ALL 13F filers (SEC structured data, Q1 2026): 3,742 holders, 1.88B shares, $215.80B reported. This is a different, older period than the tracked-universe figures above and the two are never mixed.
What else this security's tracked holders most often hold: shared-ownership counts, not fundamental relationships.
Open-market purchases (P)
No open-market insider purchases in our coverage window.
Open-market sales (S)
Officer · 10.00K sh · $1.35M
Officer · 80.31K sh · $10.72M
Officer · 11.10K sh · $1.46M
Officer · 600 sh · $79,222
Officer · 5.43K sh · $718,261
Officer · 7.41K sh · $973,165
Officer · 20.78K sh · $2.71M
Officer · 805 sh · $105,472
Officer · 4.95K sh · $643,993
Officer · 300 sh · $39,307
Awards, exercises and tax withholding are never counted as buys or sales here. Methodology