Quest Diagnostics
DGX · NYSE
Who owns DGX
Largest institutional holders, from their latest 13F filings
The 10 largest institutions hold 41.2% of DGX’s shares.
- Vanguard Capital Management, LLC6.6%
- BlackRock Institutional Trust Company, N.A.5.7%
- Vanguard Portfolio Management, LLC5.6%
- State Street Investment Management (US)5.0%
- Next 6 largest institutions18.4%
- All other shareholders58.8%
| Holder | Shares | % of shares |
|---|---|---|
| Vanguard Capital Management, LLC | 7.23M | 6.55% |
| BlackRock Institutional Trust Company, N.A. | 6.25M | 5.66% |
| Vanguard Portfolio Management, LLC | 6.13M | 5.55% |
| State Street Investment Management (US) | 5.52M | 5.00% |
| T. Rowe Price Associates, Inc. | 5.27M | 4.77% |
| Boston Partners | 4.74M | 4.30% |
| Geode Capital Management, L.L.C. | 3.14M | 2.84% |
| JP Morgan Asset Management | 2.97M | 2.69% |
| EdgePoint Investment Group Inc. | 2.25M | 2.04% |
| Dimensional Fund Advisors, L.P. | 1.99M | 1.80% |
Largest mutual fund holders
| Holder | Shares | % of shares |
|---|---|---|
| Vanguard Total Stock Market Index Fund | 3.52M | 3.19% |
| Vanguard 500 Index Fund | 2.91M | 2.63% |
| Vanguard Mid-Cap Index Fund | 2.40M | 2.17% |
| iShares Core S&P 500 ETF | 1.47M | 1.33% |
| Fidelity 500 Index Fund | 1.43M | 1.30% |
Insider trades
Form 4 filings by officers, directors and large holders
Over the last 6 months, insiders sold $11.89M (7 trades) of DGX on the open market, with no buys.
| Insider | Type | Shares | Value |
|---|---|---|---|
| WENTWORTH TIMOTHY C | Award | 135 | — |
| Davis J. E. | Sale | 10.00K | $2.43M |
| PREVOZNIK MICHAEL E | Option exercise | 22.68K | $2.54M |
| PREVOZNIK MICHAEL E | Gift | 1.00K | — |
| PREVOZNIK MICHAEL E | Sale | 430 | $105.14K |
| PREVOZNIK MICHAEL E | Sale | 6.24K | $1.52M |
| PREVOZNIK MICHAEL E | Sale | 16.01K | $3.89M |
| PREVOZNIK MICHAEL E | Option exercise | 22.68K | $2.54M |
| DELANEY MARK E | Sale | 1.60K | $376.29K |
| KUPPUSAMY KARTHIK | Other | 37 | $7.65K |
Congressional trades
Disclosed by members of Congress over the last 12 months
| Member | Type | Amount | Traded |
|---|---|---|---|
| Alan ArmstrongSenator | Purchase | $1K–$15K | Mar 30, 2026 |
| Alan ArmstrongSenator | Purchase | $1K–$15K | Mar 27, 2026 |
| Julie JohnsonHouse | Sale | $1K–$15K | Nov 3, 2025 |
Short interest
Settled Sep 30, 2026
- Shares short
- 3.42M
- Days to cover
- 2.69
- % of shares outstanding
- 3.10%
- Average daily volume
- 1.27M
- Change since last report
- −5.1%
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