Quest Diagnostics Incorporated (DGX)
Who owns Quest Diagnostics Incorporated (DGX)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 99.5% of the shares are freely tradable; institutional investors hold 97.9%.
Ownership Structure
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard Group Inc | 13.00 | 14,392,082 | +1.0 | 12/31/2025 |
| BlackRock Inc | 8.29 | 9,172,292 | -3.0 | 03/31/2026 |
| Vanguard Capital Management, LLC | 6.46 | 7,145,672 | +0.0 | 03/31/2026 |
| T. Rowe Price Associates, Inc. | 5.69 | 6,297,987 | +0.0 | 03/31/2026 |
| Vanguard Portfolio Management, LLC | 5.49 | 6,081,400 | +0.0 | 03/31/2026 |
| State Street Corp | 4.86 | 5,380,821 | +0.0 | 03/31/2026 |
| Boston Partners Global Investors, Inc | 3.62 | 4,012,232 | +2.5 | 03/31/2026 |
| JPMorgan Chase & Co | 3.47 | 3,846,456 | -7.2 | 03/31/2026 |
| Geode Capital Management, LLC | 2.79 | 3,086,308 | +1.9 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard Total Stock Mkt Idx Inv | 3.16 | 3,497,589 | +0.2 | 04/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| 28. Jul 2026 | Delaney Mark E | SVP & Chief Commercial Officer | Sell | 1,600 | 235.18 | 376,288 |
| 22. Jul 2026 | Kuppusamy Karthik | SVP, Clinical Solutions | Other | 37 | 206.81 | 7,652 |
| 22. Jul 2026 | Carter Robert B | Director | Other | 11 | 206.80 | 2,275 |
| 22. Jul 2026 | Gregg Vicky B | Director | Other | 72 | 206.81 | 14,890 |
| 22. Jul 2026 | Plewman Patrick | SVP for Diagnostic Services | Other | 46 | 206.81 | 9,513 |
| 22. Jul 2026 | Main Timothy L | Director | Other | 21 | 206.81 | 4,343 |
| 22. Jul 2026 | Samad Sam | Executive Vice President & CFO | Other | 102 | 206.81 | 21,094 |
| 22. Jul 2026 | Lassiter Wright III | Director | Other | 6 | 206.81 | 1,241 |
| 22. Jul 2026 | Delaney Mark E | SVP & Chief Commercial Officer | Other | 34 | 206.81 | 7,031 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character.
View all insider transactions →Data as of: July 31, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.