Quest Diagnostics Incorporated (DGX) has 20 known insider and institutional holders on record. The largest holder is RUSCKOWSKI STEPHEN H with 389,597 shares. Other notable holders include Davis J. E. and GUINAN MARK.
Over the last 12 months, insiders have made 95 transactions in DGX stock — 47 buys (valued at $27.31M) and 18 sells (valued at $8.15M). Insider buying has outpaced selling during this period, which may signal confidence in the company's prospects.
DGX Insider Ownership
Top Holder
RUSCKOWSKI STEPHEN H
389,597 shares
Buys (12 mo)
47
$27.31M value
Sells (12 mo)
18
$8.15M value
12-Month Transaction Activity
Top Insider Holders
| # |
Name |
Role |
Shares Owned |
Last Filed |
Relative Size |
| 1 |
Rusckowski Stephen H |
Director |
389,597 |
2023-03-08 |
|
| 2 |
Davis J. E. |
CEO and President |
142,423 |
2026-03-06 |
|
| 3 |
Guinan Mark |
Executive Vice President & CFO |
98,981 |
2022-03-09 |
|
| 4 |
Doherty Catherine T. |
EVP, Regional Businesses |
72,680 |
2026-03-06 |
|
| 5 |
Eglinton Manner Carrie |
SVP, Advanced Diagnostics |
48,391 |
2022-03-09 |
|
| 6 |
Prevoznik Michael E |
SVP & General Counsel |
41,435 |
2026-03-06 |
|
| 7 |
Cunningham Everett |
SVP, Commercial |
37,760 |
2019-03-25 |
|
| 8 |
Deppe Michael J |
SVP, Corp. Controller & CAO |
35,196 |
2026-03-06 |
|
| 9 |
Samad Sam |
Executive Vice President & CFO |
33,268 |
2026-03-06 |
|
| 10 |
Pfeiffer Gary M |
Director |
29,431 |
2025-10-24 |
|
| 11 |
Stanzione Daniel |
Director |
28,349 |
2020-11-24 |
|
| 12 |
Mendez Manuel O. |
SVP & Chief Commercial Officer |
27,633 |
2021-02-22 |
|
| 13 |
Main Timothy L |
Director |
26,297 |
2025-05-19 |
|
| 14 |
Wilensky Gail R |
Director |
20,506 |
2023-05-19 |
|
| 15 |
Cohen Jon R |
SVP & Group Exec. Diag. Sol. |
19,464 |
2018-03-12 |
|
| 16 |
Plewman Patrick |
SVP For Diagnostic Services |
18,053 |
2026-03-06 |
|
| 17 |
Gregg Vicky B |
Director |
17,104 |
2026-02-20 |
|
| 18 |
Ring Timothy M |
Director |
17,036 |
2025-10-03 |
|
| 19 |
Britell Jenne K |
Director |
14,479 |
2018-06-06 |
|
| 20 |
Kuppusamy Karthik |
SVP, Clinical Solutions |
13,441 |
2026-03-06 |
|
Recent Transactions (last 12 months)
| Date |
Name |
Role |
Type |
Shares |
Price |
Value |
| 2026-04-01 |
Wentworth Timothy C |
Director |
RSU Award |
198 |
- |
- |
| 2026-03-09 |
Wentworth Timothy C |
Director |
RSU Award |
215 |
- |
- |
| 2026-03-09 |
Wentworth Timothy C |
Director |
Unknown |
- |
- |
- |
| 2026-03-04 |
Delaney Mark E |
SVP & Chief Commercial Officer |
Tax Withholding of RSU |
2,326 |
$204.86 |
$476.5K |
| 2026-03-04 |
Kuppusamy Karthik |
SVP, Clinical Solutions |
Informative Sell |
2,628 |
$204.86 |
$538.37K |
| 2026-03-04 |
Deppe Michael J |
SVP, Corp. Controller & CAO |
Tax Withholding of RSU |
750 |
$204.86 |
$153.65K |
| 2026-03-04 |
Samad Sam |
Executive Vice President & CFO |
Tax Withholding of RSU |
7,720 |
$204.86 |
$1.58M |
| 2026-03-04 |
Davis J. E. |
CEO and President |
Tax Withholding of RSU |
26,414 |
$204.86 |
$5.41M |
| 2026-03-05 |
Doherty Catherine T. |
EVP, Regional Businesses |
Informative Sell |
5,558 |
$206.21 |
$1.15M |
| 2026-03-04 |
Doherty Catherine T. |
EVP, Regional Businesses |
Tax Withholding of RSU |
5,806 |
$204.86 |
$1.19M |
| 2026-03-05 |
Plewman Patrick |
SVP For Diagnostic Services |
Informative Sell |
2,855 |
$206.21 |
$588.73K |
| 2026-03-04 |
Plewman Patrick |
SVP For Diagnostic Services |
Tax Withholding of RSU |
2,827 |
$204.86 |
$579.14K |
| 2026-03-05 |
Prevoznik Michael E |
SVP & General Counsel |
Informative Sell |
3,878 |
$206.21 |
$799.68K |
| 2026-03-04 |
Prevoznik Michael E |
SVP & General Counsel |
Tax Withholding of RSU |
3,354 |
$204.86 |
$687.1K |
| 2026-03-02 |
Delaney Mark E |
SVP & Chief Commercial Officer |
Tax Withholding of RSU |
188 |
$204.86 |
$38.51K |
| 2026-03-02 |
Kuppusamy Karthik |
SVP, Clinical Solutions |
Tax Withholding of RSU |
205 |
$204.86 |
$42K |
| 2026-03-02 |
Deppe Michael J |
SVP, Corp. Controller & CAO |
Tax Withholding of RSU |
88 |
$204.86 |
$18.03K |
| 2026-03-02 |
Samad Sam |
Executive Vice President & CFO |
Tax Withholding of RSU |
869 |
$204.86 |
$178.02K |
| 2026-03-02 |
Davis J. E. |
CEO and President |
Informative Sell |
10,000 |
$212.52 |
$2.13M |
| 2026-03-03 |
Doherty Catherine T. |
EVP, Regional Businesses |
Informative Sell |
632 |
$207.73 |
$131.29K |
| 2026-03-02 |
Doherty Catherine T. |
EVP, Regional Businesses |
Tax Withholding of RSU |
648 |
$204.86 |
$132.75K |
| 2026-03-03 |
Plewman Patrick |
SVP For Diagnostic Services |
Informative Sell |
410 |
$207.73 |
$85.17K |
| 2026-03-02 |
Plewman Patrick |
SVP For Diagnostic Services |
Tax Withholding of RSU |
230 |
$204.86 |
$47.12K |
| 2026-03-03 |
Prevoznik Michael E |
SVP & General Counsel |
Informative Sell |
526 |
$207.73 |
$109.27K |
| 2026-03-02 |
Prevoznik Michael E |
SVP & General Counsel |
Tax Withholding of RSU |
288 |
$204.86 |
$59K |
