Comparable stake leader
BlackRock, Inc.
SEC ownership of QUEST DIAGNOSTICS INC
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001022079.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
20 May 2026
- Public ticker
- DGX on NYSE
- Parsed ownership sources
- 13F, 13D/G, and 3/4/5
- Largest SEC-reported holder
- BlackRock, Inc.
- Latest 13D/G holder
- BlackRock, Inc.
- Latest parsed ownership date
- 20 May 2026
- Issuer CIK
- 0001022079
- Issuer location
- Secaucus, NJ
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of QUEST DIAGNOSTICS INC (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
BlackRock, Inc.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
20 May 2026
13F
13D/G
3/4/5
Lead comparable stake: 8.4%
13D/G row: BlackRock, Inc.
Showing 1-8 of 50 holder rows.
Quick read
BlackRock, Inc. leads the comparable SEC ownership view at 8.4%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens BlackRock, Inc.'s linked filing trail.
Comparable ownership
Top 5
BlackRock, Inc.
8.4%
VANGUARD CAPITAL MANAGEMENT LLC
7.5%
PRICE T ROWE ASSOCIATES INC /MD/
6.5%
VANGUARD PORTFOLIO MANAGEMENT LLC
5.5%
Gary M. Pfeiffer
0.03%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| BlackRock, Inc. |
13F
13D/G
Company
|
8.4%
from 13D/G
|
$1,797,585,732
9,172,292 shares
|
— | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
13F
Vanguard Capital Management · Company
|
7.5%
|
$1,621,649,641
8,274,567 shares
|
$0 | 31 Mar 2026 |
| PRICE T ROWE ASSOCIATES INC /MD/ |
13D/G
13F
T. Rowe Price Associates, Inc. · Company
|
6.5%
|
$1,275,526,324
7,209,622 shares
|
+$214,831,656 | 30 Jun 2025 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13D/G
13F
Vanguard Portfolio Management · Company
|
5.5%
|
$1,194,817,351
6,096,629 shares
|
$0 | 31 Mar 2026 |
| Gary M. Pfeiffer |
3/4/5
Director
|
0.03%
|
$6,076,359
31,005 shares
|
-$270,317 | 20 May 2026 |
| Timothy L. Main |
3/4/5
Director
|
0.02%
|
$5,377,495
27,439 shares
|
— | 20 May 2026 |
| Vicky B. Gregg |
3/4/5
Director
|
0.02%
|
$3,589,177
18,314 shares
|
-$239,700 | 20 May 2026 |
| Denise M. Morrison |
3/4/5
Director
|
0.01%
|
$2,337,845
11,929 shares
|
— | 20 May 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$36,967,391.
Buys
$0
Insiders: 0
Sells
$36,967,391
Insiders: 8
Net
-$36,967,391
Shares: -190,773
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 190,773
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 22,291 | $0 | $4,475,927 | -$4,475,927 |
| 3-6 | 0 | 49,525 | $0 | $10,255,470 | -$10,255,470 |
| 6-9 | 0 | 94,461 | $0 | $17,957,208 | -$17,957,208 |
| 9-12 | 0 | 24,496 | $0 | $4,278,787 | -$4,278,787 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 24 reporting-owner rows connected to QUEST DIAGNOSTICS INC. Open a relationship link for the CIK-to-CIK filing trail.
Rows
24
Largest Forms 3/4/5 holder
Stephen H. Rusckowski
Net 12M change
-$36,967,392
Latest report
01 Jun 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Stephen H. Rusckowski | Director | $47,867,056 | Mixed | 06 Mar 2023 | ||
| J. E. Davis | CEO and President, Director | $25,708,601 | -$14,656,360 | -36% | Filing P/S | 01 Jun 2026 |
| Catherine T. Doherty | EVP, Regional Businesses | $14,702,234 | -$6,964,737 | -32% | Mixed | 04 Mar 2026 |
| Mark Guinan | Executive Vice President & CFO | $13,108,142 | Mixed | 07 Mar 2022 | ||
| Michael E. Prevoznik | SVP & General Counsel | $8,841,829 | -$6,505,262 | -42% | Mixed | 04 Mar 2026 |
| Timothy M. Ring | Director | $8,838,455 | Mixed | 20 May 2026 | ||
| Sam Samad | Executive Vice President & CFO | $8,048,650 | Mixed | 20 Apr 2026 | ||
| Manner Carrie Eglinton | SVP, Advanced Diagnostics | $7,592,213 | Mixed | 07 Mar 2022 | ||
| Michael J. Deppe | SVP, Corp. Controller & CAO | $6,881,798 | Mixed | 04 Mar 2026 | ||
| Gary M. Pfeiffer | Director | $6,076,359 | -$270,317 | -4.3% | Median | 20 May 2026 |
| Timothy L. Main | Director | $5,377,495 | Median | 20 May 2026 | ||
| Gail R. Wilensky | Director | $4,162,722 | Mixed | 17 May 2023 | ||
| Vicky B. Gregg | Director | $3,589,177 | -$239,700 | -6.3% | Median | 20 May 2026 |
| Mark E. Delaney | SVP & Chief Commercial Officer | $3,405,038 | -$1,488,683 | -30% | Mixed | 20 Apr 2026 |
| Karthik Kuppusamy | SVP, Clinical Solutions | $3,057,090 | -$2,298,303 | -43% | Median | 20 Apr 2026 |
| Patrick Plewman | SVP for Diagnostic Services | $2,988,107 | -$4,544,030 | -60% | Median | 20 Apr 2026 |
| Denise M. Morrison | Director | $2,337,845 | Median | 20 May 2026 | ||
| Wright Lassiter III | Director | $2,081,926 | Mixed | 20 May 2026 | ||
| Mark A. Gardner | SVP of Molecular Gen & Oncol | $1,539,829 | Mixed | 24 Sep 2024 | ||
| Tracey C. Doi | Director | $1,518,453 | Median | 20 May 2026 |
Recent insider transactions for QUEST DIAGNOSTICS INC
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| J. E. Davis | DGX | Common Stock | Sale | -7.02% | $1,941,400 | $194.14 | -10,000 | 132,423 | 01 Jun 2026 | Direct |
| Robert B. Carter | DGX | Common Stock | Award | 42.1% | 1,142 | 3,853 | 20 May 2026 | Direct | ||
| Vicky B. Gregg | DGX | Common Stock | Award | 6.65% | 1,142 | 18,314 | 20 May 2026 | Direct | ||
| Luis Diaz | DGX | Common Stock | Award | 28.2% | 1,142 | 5,196 | 20 May 2026 | Direct | ||
| Timothy L. Main | DGX | Common Stock | Award | 4.34% | 1,142 | 27,439 | 20 May 2026 | Direct | ||
| Timothy C. Wentworth | DGX | Common Stock | Award | 528.7% | 1,142 | 1,358 | 20 May 2026 | Direct | ||
| Tracey C. Doi | DGX | Common Stock | Award | 17.3% | 1,142 | 7,748 | 20 May 2026 | Direct | ||
| Timothy M. Ring | DGX | Common Stock | Award | 3.81% | 1,142 | 31,140 | 20 May 2026 | Direct | ||
| Wright Lassiter III | DGX | Common Stock | Award | 12.4% | 1,142 | 10,317 | 20 May 2026 | Direct | ||
| Denise M. Morrison | DGX | Common Stock | Award | 10.6% | 1,142 | 11,929 | 20 May 2026 | Direct | ||
| Gary M. Pfeiffer | DGX | Common Stock | Award | 3.82% | 1,142 | 31,005 | 20 May 2026 | Direct | ||
| Sam Samad | DGX | Common Stock | Award | 0.32% | 108 | 33,376 | 20 Apr 2026 | Direct | ||
| Patrick Plewman | DGX | Common Stock | Small acquisition under Rule 16a-6 | 0.32% | 49 | 15,247 | 20 Apr 2026 | Direct | ||
| Vicky B. Gregg | DGX | Common Stock | Award | 0.4% | 68 | 17,172 | 20 Apr 2026 | Direct | ||
| Robert B. Carter | DGX | Common Stock | Small acquisition under Rule 16a-6 | 0.26% | 7 | 2,711 | 20 Apr 2026 | Direct | ||
| Wright Lassiter III | DGX | Common Stock | Small acquisition under Rule 16a-6 | 0.07% | 6 | 9,063 | 20 Apr 2026 | Direct | ||
| Karthik Kuppusamy | DGX | Common Stock | Small acquisition under Rule 16a-6 | 0.29% | 39 | 13,490 | 20 Apr 2026 | Direct | ||
| Mark E. Delaney | DGX | Common Stock | Small acquisition under Rule 16a-6 | 0.31% | 37 | 11,901 | 20 Apr 2026 | Direct | ||
| Timothy C. Wentworth | DGX | Phantom Stock Units | Award | 198 | 198 | 01 Apr 2026 | Direct | |||
| Timothy C. Wentworth | DGX | Common Stock | Award | 215 | 215 | 09 Mar 2026 | Direct | |||
| Catherine T. Doherty | DGX | Common Stock | Sale | -7.65% | $1,146,115 | $206.21 | -5,558 | 67,122 | 05 Mar 2026 | Direct |
| Michael E. Prevoznik | DGX | Common Stock | Sale | -9.36% | $799,682 | $206.21 | -3,878 | 37,557 | 05 Mar 2026 | Direct |
| Patrick Plewman | DGX | Common Stock | Sale | -15.8% | $588,730 | $206.21 | -2,855 | 15,198 | 05 Mar 2026 | Direct |
| Sam Samad | DGX | Common Stock | Tax liability | -18.8% | -7,720 | 33,268 | 04 Mar 2026 | Direct | ||
| Sam Samad | DGX | Common Stock | Award | 51.6% | 13,947 | 40,988 | 04 Mar 2026 | Direct | ||
| Catherine T. Doherty | DGX | Common Stock | Tax liability | -7.4% | -5,806 | 72,680 | 04 Mar 2026 | Direct | ||
| Catherine T. Doherty | DGX | Common Stock | Award | 16.9% | 11,364 | 78,486 | 04 Mar 2026 | Direct | ||
| Mark E. Delaney | DGX | Common Stock | Tax liability | -16.4% | -2,326 | 11,864 | 04 Mar 2026 | Direct | ||
| Mark E. Delaney | DGX | Common Stock | Award | 66.8% | 5,682 | 14,190 | 04 Mar 2026 | Direct | ||
| Michael E. Prevoznik | DGX | Common Stock | Tax liability | -7.49% | -3,354 | 41,435 | 04 Mar 2026 | Direct | ||
| Michael E. Prevoznik | DGX | Common Stock | Award | 19.3% | 7,232 | 44,789 | 04 Mar 2026 | Direct | ||
| J. E. Davis | DGX | Common Stock | Tax liability | -15.6% | -26,414 | 142,423 | 04 Mar 2026 | Direct | ||
| J. E. Davis | DGX | Common Stock | Award | 44.1% | 51,652 | 168,837 | 04 Mar 2026 | Direct | ||
| Patrick Plewman | DGX | Common Stock | Tax liability | -13.5% | -2,827 | 18,053 | 04 Mar 2026 | Direct | ||
| Patrick Plewman | DGX | Common Stock | Award | 37.4% | 5,682 | 20,880 | 04 Mar 2026 | Direct | ||
| Michael J. Deppe | DGX | Common Stock | Tax liability | -2.09% | -750 | 35,196 | 04 Mar 2026 | Direct | ||
| Michael J. Deppe | DGX | Common Stock | Award | 4.27% | 1,473 | 35,946 | 04 Mar 2026 | Direct | ||
| Karthik Kuppusamy | DGX | Common Stock | Sale | -16.4% | $538,372 | $204.86 | -2,628 | 13,441 | 04 Mar 2026 | Direct |
| Karthik Kuppusamy | DGX | Common Stock | Award | 62.8% | 6,200 | 16,069 | 04 Mar 2026 | Direct | ||
| Catherine T. Doherty | DGX | Common Stock | Sale | -0.93% | $131,285 | $207.73 | -632 | 67,122 | 03 Mar 2026 | Direct |
| Michael E. Prevoznik | DGX | Common Stock | Sale | -1.38% | $109,266 | $207.73 | -526 | 37,557 | 03 Mar 2026 | Direct |
| Patrick Plewman | DGX | Common Stock | Sale | -2.63% | $85,169 | $207.73 | -410 | 15,198 | 03 Mar 2026 | Direct |
| Catherine T. Doherty | DGX | Common Stock | Tax liability | -0.95% | -648 | 67,754 | 02 Mar 2026 | Direct | ||
| Sam Samad | DGX | Common Stock | Tax liability | -3.11% | -869 | 27,041 | 02 Mar 2026 | Direct | ||
| Michael E. Prevoznik | DGX | Common Stock | Tax liability | -0.75% | -288 | 38,083 | 02 Mar 2026 | Direct | ||
| J. E. Davis | DGX | Common Stock | Sale | -7.86% | $2,125,200 | $212.52 | -10,000 | 117,185 | 02 Mar 2026 | Direct |
| J. E. Davis | DGX | Common Stock | Tax liability | -2.28% | -2,968 | 127,185 | 02 Mar 2026 | Direct | ||
| Patrick Plewman | DGX | Common Stock | Tax liability | -1.45% | -230 | 15,608 | 02 Mar 2026 | Direct | ||
| Karthik Kuppusamy | DGX | Common Stock | Tax liability | -2.03% | -205 | 9,869 | 02 Mar 2026 | Direct | ||
| Mark E. Delaney | DGX | Common Stock | Tax liability | -2.16% | -188 | 8,508 | 02 Mar 2026 | Direct |
* marks a reported price that did not pass the local price check.