Quest Diagnostics Incorporated (DGX) Shareholders & Insider Trades
Quest Diagnostics shareholders at a glance
The largest holder of Quest Diagnostics stock is Vanguard Capital Management LLC, with 7.2 million shares (6.55% of the company), worth about $1.74 billion as of September 25, 2026. The 10 largest holders together own 43.1%.
In Q2 2026, 1,141 institutional holdings reports listed shares worth $22.30 billion.
Insiders reported 98 transactions in the last two years: 30 sales worth $42.20 million and 18 purchases. The newest one on file is from April 20, 2026 (Plewman Patrick, Officer).
Major holders as of September 25, 2026; quarterly totals from institutional holdings reports (latest Q2 2026); insider transactions on file through April 20, 2026.
Quest Diagnostics Incorporated
Shareholders Summary
2026Q2
Ownership by Type
Geographic Distribution
Largest Quest Diagnostics shareholders
| Holder | Shares | % of company | Value |
|---|---|---|---|
| Vanguard Capital Management LLC | 7.2 million | 6.55% | $1.7B |
| BlackRock Advisors LLC | 7.2 million | 6.50% | $1.7B |
| Vanguard Portfolio Management LLC | 6.1 million | 5.55% | $1.5B |
| State Street Corporation | 5.5 million | 5.00% | $1.3B |
| T. Rowe Price International Ltd. | 5.4 million | 4.93% | $1.3B |
| Boston Partners Global Investors, Inc. | 4.7 million | 4.30% | $1.1B |
| JPMorgan Investment Management, Inc. | 3.5 million | 3.19% | $846.0M |
| Geode Capital Management LLC | 3.1 million | 2.84% | $754.0M |
| Eaton Vance Management | 2.5 million | 2.23% | $591.0M |
| Edgepoint Investment Group, Inc. | 2.2 million | 2.04% | $540.0M |
As of September 25, 2026.
Quest Diagnostics institutional holdings by quarter
| Quarter | Reports | Shares | Value |
|---|---|---|---|
| Q2 2026 | 1,141 | – | $22.3B |
| Q1 2026 | 1,090 | 103.0 million | $20.1B |
| Q4 2025 | 1,080 | 107.0 million | $18.4B |
| Q3 2025 | 1,041 | 109.0 million | $20.8B |
| Q2 2025 | 1,030 | 109.0 million | $19.5B |
| Q1 2025 | 1,008 | 104.0 million | $17.5B |
| Q4 2024 | 935 | 99.6 million | $15.0B |
| Q3 2024 | 886 | 101.0 million | $15.5B |
Shares and value held by institutions that file quarterly holdings reports (options not included).
Quest Diagnostics insider trades
| Insider | Date | Title | Transaction | Value |
|---|---|---|---|---|
| Plewman Patrick | Apr 20, 2026 | Officer | Purchase at price 194.70 per share. | $9,540 |
| Lassiter Wright Iii | Apr 20, 2026 | Director | Purchase at price 194.70 per share. | $1,168 |
| Kuppusamy Karthik | Apr 20, 2026 | Officer | Purchase at price 194.70 per share. | $7,593 |
| Delaney Mark E | Apr 20, 2026 | Officer | Purchase at price 194.70 per share. | $7,204 |
| Gregg Vicky B | Apr 20, 2026 | Director | Stock Award(Grant) at price 194.70 per share. | $13,239 |
| Samad Samer Abdul | Apr 20, 2026 | Chief Financial Officer | Stock Award(Grant) at price 194.70 per share. | $21,027 |
| Wentworth Timothy Charles | Mar 9, 2026 | Director | Stock Award(Grant) at price 0.00 per share. | – |
| Plewman Patrick | Mar 5, 2026 | Officer | Sale at price 206.21 per share. | $588,730 |
| Doherty Catherine T | Mar 5, 2026 | Officer | Sale at price 206.21 per share. | $1.1M |
| Prevoznik Michael E | Mar 5, 2026 | General Counsel | Sale at price 206.21 per share. | $799,682 |
| Samad Samer Abdul | Mar 4, 2026 | Chief Financial Officer | Stock Award(Grant) at price 204.86 per share. | $2.9M |
| Deppe Michael J | Mar 4, 2026 | Officer | Stock Award(Grant) at price 204.86 per share. | $301,759 |
Newest 12 of 98 insider transactions in the last two years.
Questions and answers
Who owns the most Quest Diagnostics stock?
Vanguard Capital Management LLC, with 6.55% of the company (as of September 25, 2026). Next: BlackRock Advisors LLC (6.50%) and Vanguard Portfolio Management LLC (5.55%).
How many institutions own Quest Diagnostics stock?
1,141 institutional holdings reports listed Quest Diagnostics shares in Q2 2026 worth $22.30 billion.
Are Quest Diagnostics insiders buying or selling the stock?
In the last two years insiders reported 30 sales and 18 purchases (98 transactions in all); the newest on file is from April 20, 2026.
