QUEST DIAGNOSTICS INC

DGX · Services-Medical Laboratories · 110.7M shares · -5%/yr ↓ buyback · EDGAR filings ↗

Net buyback after stock comp: $198M (gross $275M, SBC $77M)

Reference price $200.00 · est. market cap ~$22.1B — last insider sale, 2026-06-04 (estimated from the dated SEC Form 4 price × shares outstanding — not a live quote)

Grade

B78

Diagnostics-lab giant — profitable with strong free cash flow and steady growth.

Strengths

Strong free cash flow — FCF $1.4B (100th), operating margin 14% (100th)
Strong asset returns — ROA 6% (100th)
Steady, scaled lab network — per 10-K

Risks

Reimbursement-rate pressure — per 10-K
Leverage — D/E 0.7 (66th)
Low gross margin (lab services) — 33%

Notable findings

Exec changeRecent 8-K item 5.02 8-K ↗
Fund exitedNotable fund(s) exited this quarter: VANGUARD GROUP INC
Strong balance sheetStrong balance sheet — $420M cash & investments
Buying back stockNet buyback — share count -5%/yr over 4y
Notable holderHeld by 5 notable fund(s): STATE STREET CORP, GOLDMAN SACHS GROUP INC, FMR LLC +2 more (as of 2026-03-31)
Insider sellingInsider selling — 19 open-market sale(s) by 5 insider(s) (cluster of 5 insiders, ~$16M, last 6mo) Form 4 ↗

Quarterly revenue

2025-06-30 · $2.8B2025-09-30 · $2.8B2025-12-31 · $2.8B2026-03-31 · $2.9B

Last 4 quarters · from SEC filings.

Key metrics

Gross margin

33.2%

Operating margin

14.1%

Net margin

9.0%

Return on equity

13.8%

Return on assets

6.1%

ROIC

10.0%

Revenue growth (QoQ)

3.2%

Net-income growth

13.9%

Debt / equity

0.7×

Net debt / EBITDA

2.2×

Current ratio

1.0×

Free cash flow

$1.4B

EBITDA

$2.1B

Tangible book value

-$3.4B

Cash & investments

$420M

Stock comp / revenue

0.8%

Insider transactions · last 18 months

Date	Insider	Type	Shares	Price
2026-06-04	KUPPUSAMY KARTHIK	Option exercise	3.3K	$127.72
2026-06-04	KUPPUSAMY KARTHIK	Sell	8.1K	$200.00
2026-06-04	KUPPUSAMY KARTHIK	Option exercise	4.8K	$121.81
2026-06-01	Davis J. E.	Sell	10K	$194.14
2026-05-20	Doi Tracey	Grant	1.1K	—
2026-05-20	Gregg Vicky B	Grant	1.1K	—
2026-05-20	WENTWORTH TIMOTHY C	Grant	1.1K	—
2026-05-20	MORRISON DENISE M	Grant	1.1K	—
2026-05-20	RING TIMOTHY M	Grant	1.1K	—
2026-05-20	MAIN TIMOTHY L	Grant	1.1K	—
2026-05-20	CARTER ROBERT B	Grant	1.1K	—
2026-05-20	Lassiter Wright III	Grant	1.1K	—
2026-05-20	PFEIFFER GARY M	Grant	1.1K	—
2026-05-20	Diaz Luis	Grant	1.1K	—
2026-04-20	KUPPUSAMY KARTHIK	L	39	$194.70
2026-04-20	DELANEY MARK E	L	37	$194.70
2026-04-20	SAMAD SAM	Grant	108	$194.70
2026-04-20	Plewman Patrick	L	49	$194.70
2026-04-20	Gregg Vicky B	Grant	68	$194.70
2026-04-20	CARTER ROBERT B	L	7	$194.70
2026-04-20	Lassiter Wright III	L	6	$194.70
2026-03-09	WENTWORTH TIMOTHY C	Grant	215	—
2026-03-05	Doherty Catherine T.	Sell	5.6K	$206.21
2026-03-05	PREVOZNIK MICHAEL E	Sell	3.9K	$206.21
2026-03-05	Plewman Patrick	Sell	2.9K	$206.21
2026-03-04	SAMAD SAM	Grant	14K	$204.86
2026-03-04	Doherty Catherine T.	Grant	11K	$204.86
2026-03-04	Doherty Catherine T.	Tax withheld	5.8K	$204.86
2026-03-04	DELANEY MARK E	Grant	5.7K	$204.86
2026-03-04	DELANEY MARK E	Tax withheld	2.3K	$204.86
2026-03-04	PREVOZNIK MICHAEL E	Grant	7.2K	$204.86
2026-03-04	PREVOZNIK MICHAEL E	Tax withheld	3.4K	$204.86
2026-03-04	Davis J. E.	Grant	52K	$204.86
2026-03-04	Davis J. E.	Tax withheld	26K	$204.86
2026-03-04	Plewman Patrick	Grant	5.7K	$204.86
2026-03-04	Plewman Patrick	Tax withheld	2.8K	$204.86
2026-03-04	Deppe Michael J	Grant	1.5K	$204.86
2026-03-04	Deppe Michael J	Tax withheld	750	$204.86
2026-03-04	KUPPUSAMY KARTHIK	Grant	6.2K	$204.86
2026-03-04	KUPPUSAMY KARTHIK	Sell	2.6K	$204.86
2026-03-04	SAMAD SAM	Tax withheld	7.7K	$204.86
2026-03-03	PREVOZNIK MICHAEL E	Sell	526	$207.73
2026-03-03	Plewman Patrick	Sell	410	$207.73
2026-03-03	Doherty Catherine T.	Sell	632	$207.73
2026-03-02	PREVOZNIK MICHAEL E	Tax withheld	288	$204.86
2026-03-02	Deppe Michael J	Tax withheld	88	$204.86
2026-03-02	KUPPUSAMY KARTHIK	Tax withheld	205	$204.86
2026-03-02	Doherty Catherine T.	Tax withheld	648	$204.86
2026-03-02	SAMAD SAM	Tax withheld	869	$204.86
2026-03-02	Davis J. E.	Sell	10K	$212.52
2026-03-02	Plewman Patrick	Tax withheld	230	$204.86
2026-03-02	DELANEY MARK E	Tax withheld	188	$204.86
2026-03-02	Davis J. E.	Tax withheld	3.0K	$204.86
2026-02-19	Plewman Patrick	Sell	958	$204.83
2026-02-19	Doherty Catherine T.	Sell	1.4K	$204.83
2026-02-19	PREVOZNIK MICHAEL E	Sell	1.1K	$204.83
2026-02-18	Davis J. E.	Tax withheld	3.8K	$206.99
2026-02-18	DELANEY MARK E	Grant	1.6K	—
2026-02-18	DELANEY MARK E	Tax withheld	205	$210.01
2026-02-18	DELANEY MARK E	Tax withheld	230	$206.99
2026-02-18	KUPPUSAMY KARTHIK	Tax withheld	252	$210.01
2026-02-18	KUPPUSAMY KARTHIK	Tax withheld	259	$206.99
2026-02-18	KUPPUSAMY KARTHIK	Grant	2.1K	—
2026-02-18	Deppe Michael J	Grant	366	—
2026-02-18	Deppe Michael J	Tax withheld	83	$210.01
2026-02-18	Deppe Michael J	Tax withheld	99	$206.99
2026-02-18	SAMAD SAM	Grant	4.0K	—
2026-02-18	SAMAD SAM	Tax withheld	855	$210.01
2026-02-18	SAMAD SAM	Tax withheld	1.0K	$206.99
2026-02-18	Davis J. E.	Grant	16K	—
2026-02-18	Davis J. E.	Tax withheld	2.4K	$210.01
2026-02-18	Doherty Catherine T.	Grant	2.9K	—
2026-02-18	Doherty Catherine T.	Tax withheld	433	$210.01
2026-02-18	Doherty Catherine T.	Tax withheld	728	$206.99
2026-02-18	Plewman Patrick	Grant	2.0K	—
2026-02-18	Plewman Patrick	Tax withheld	244	$210.01
2026-02-18	Plewman Patrick	Tax withheld	293	$206.99
2026-02-18	PREVOZNIK MICHAEL E	Grant	2.0K	—
2026-02-18	PREVOZNIK MICHAEL E	Tax withheld	301	$210.01
2026-02-18	PREVOZNIK MICHAEL E	Tax withheld	347	$206.99
2026-02-13	Doherty Catherine T.	Option exercise	26K	$112.17
2026-02-13	Doherty Catherine T.	Sell	11K	$205.21
2026-02-13	Doherty Catherine T.	Sell	10K	$206.37
2026-02-13	Doherty Catherine T.	Sell	3.5K	$207.08
2026-02-13	Doherty Catherine T.	Sell	1.6K	$208.21
2026-02-13	Doherty Catherine T.	Sell	351	$209.10
2026-02-10	Plewman Patrick	Sell	5.7K	$204.00
2026-02-10	Plewman Patrick	Option exercise	5.7K	$121.81
2026-01-28	SAMAD SAM	Grant	69	$183.51
2026-01-28	DELANEY MARK E	L	15	$183.51
2026-01-28	Gregg Vicky B	L	67	$183.51
2026-01-28	KUPPUSAMY KARTHIK	L	16	$183.52
2026-01-28	CARTER ROBERT B	L	6	$183.51
2026-01-28	Lassiter Wright III	L	7	$183.51
2026-01-28	Plewman Patrick	Grant	48	$183.51
2025-11-25	Davis J. E.	Sell	4.7K	$192.97
2025-11-25	Gregg Vicky B	Sell	1.2K	$191.76
2025-11-25	Davis J. E.	Option exercise	55K	$95.80
2025-11-25	Davis J. E.	Sell	9.3K	$191.59
2025-11-25	Davis J. E.	Sell	41K	$192.27
2025-11-18	DELANEY MARK E	Sell	7.9K	$187.35
2025-11-18	DELANEY MARK E	Option exercise	7.8K	$144.47
2025-11-18	DELANEY MARK E	Option exercise	100	$143.33
2025-11-05	Davis J. E.	Tax withheld	7.1K	$175.57
2025-10-22	PFEIFFER GARY M	Sell	1.5K	$182.40
2025-10-21	DELANEY MARK E	Grant	15	$189.08
2025-10-21	SAMAD SAM	Grant	68	$189.08
2025-10-21	Plewman Patrick	Grant	46	$189.08
2025-10-21	KUPPUSAMY KARTHIK	Grant	15	$189.08
2025-10-21	Gregg Vicky B	Grant	70	$189.08
2025-10-21	CARTER ROBERT B	Grant	6	$189.09
2025-09-26	PREVOZNIK MICHAEL E	Sell	144	$188.66
2025-09-26	PREVOZNIK MICHAEL E	Sell	83	$187.22
2025-09-26	PREVOZNIK MICHAEL E	Option exercise	227	$103.57
2025-09-24	PREVOZNIK MICHAEL E	Option exercise	175	$103.57
2025-09-24	PREVOZNIK MICHAEL E	Sell	175	$187.02
2025-09-23	PREVOZNIK MICHAEL E	Sell	28K	$187.12
2025-09-23	PREVOZNIK MICHAEL E	Option exercise	28K	$103.57
2025-08-21	Plewman Patrick	Sell	2.0K	$185.00
2025-08-19	Plewman Patrick	Option exercise	4.5K	$112.17
2025-08-19	Plewman Patrick	Sell	4.5K	$183.00
2025-08-15	Plewman Patrick	Sell	2.0K	$180.00
2025-08-13	KUPPUSAMY KARTHIK	Tax withheld	123	$175.91
2025-08-06	Plewman Patrick	Sell	3.6K	$175.00
2025-08-06	Plewman Patrick	Sell	2.0K	$175.00
2025-08-06	Plewman Patrick	Option exercise	3.6K	$86.63
2025-07-31	KUPPUSAMY KARTHIK	Sell	2.2K	$170.00
2025-07-30	KUPPUSAMY KARTHIK	Option exercise	5.2K	$112.17
2025-07-30	KUPPUSAMY KARTHIK	Option exercise	3.0K	$86.63
2025-07-30	KUPPUSAMY KARTHIK	Sell	3.0K	$167.40
2025-07-30	KUPPUSAMY KARTHIK	Sell	5.2K	$167.40
2025-07-21	Lassiter Wright III	L	7	$167.50
2025-07-21	Gregg Vicky B	L	79	$167.50
2025-07-21	SAMAD SAM	L	72	$167.50
2025-07-21	Plewman Patrick	L	80	$167.49
2025-07-21	KUPPUSAMY KARTHIK	L	27	$167.50
2025-07-21	DELANEY MARK E	L	17	$167.49
2025-07-21	CARTER ROBERT B	L	7	$167.50
2025-07-16	SAMAD SAM	Tax withheld	850	$169.01
2025-05-15	CARTER ROBERT B	Grant	1.2K	—
2025-05-15	Diaz Luis	Grant	1.2K	—
2025-05-15	Gregg Vicky B	Grant	1.2K	—
2025-05-15	Doi Tracey	Grant	1.2K	—
2025-05-15	MAIN TIMOTHY L	Grant	1.2K	—
2025-05-15	MORRISON DENISE M	Grant	1.2K	—
2025-05-15	Lassiter Wright III	Grant	1.2K	—
2025-05-15	RING TIMOTHY M	Grant	1.2K	—
2025-05-15	PFEIFFER GARY M	Grant	1.2K	—
2025-05-13	DELANEY MARK E	Sell	874	$175.31
2025-05-12	DELANEY MARK E	Sell	874	$175.72
2025-04-21	Gregg Vicky B	Grant	68	$164.42
2025-04-21	KUPPUSAMY KARTHIK	L	27	$164.42
2025-04-21	SAMAD SAM	L	74	$164.42
2025-04-21	DELANEY MARK E	L	25	$164.42
2025-04-21	Plewman Patrick	L	81	$164.42
2025-04-02	Davis J. E.	Sell	5.9K	$168.66
2025-04-02	Davis J. E.	Sell	2.5K	$169.57
2025-04-02	Davis J. E.	Sell	750	$167.86
2025-04-02	Davis J. E.	Sell	584	$168.70
2025-04-02	Davis J. E.	Sell	267	$169.60
2025-04-02	Davis J. E.	Sell	1.5K	$167.88
2025-04-02	Davis J. E.	Sell	902	$168.79
2025-04-02	Davis J. E.	Sell	453	$169.63
2025-04-02	KUPPUSAMY KARTHIK	Sell	2.6K	$170.00
2025-04-02	Davis J. E.	Sell	7.0K	$167.86
2025-04-02	Davis J. E.	Sell	2.4K	$168.03
2025-04-02	Davis J. E.	Sell	1.4K	$168.76
2025-04-02	Davis J. E.	Sell	704	$169.63
2025-04-02	Davis J. E.	Sell	7.2K	$167.86
2025-04-02	Davis J. E.	Sell	4.9K	$168.72
2025-04-02	Davis J. E.	Sell	2.8K	$169.56
2025-03-26	Plewman Patrick	Tax withheld	162	$166.71
2025-03-26	DELANEY MARK E	Tax withheld	256	$166.71
2025-03-17	PREVOZNIK MICHAEL E	Sell	4.6K	$170.00
2025-03-05	Doherty Catherine T.	Sell	5.4K	$174.13
2025-03-04	Plewman Patrick	Tax withheld	2.3K	$173.74
2025-03-04	DEPPE MICHAEL J	Grant	1.7K	$173.74
2025-03-04	DEPPE MICHAEL J	Tax withheld	867	$173.74
2025-03-04	Doherty Catherine T.	Sell	716	$175.79
2025-03-04	Doherty Catherine T.	Grant	10K	$173.74
2025-03-04	Doherty Catherine T.	Tax withheld	5.0K	$173.74
2025-03-04	Davis J. E.	Grant	62K	$173.74
2025-03-04	Davis J. E.	Tax withheld	32K	$173.74
2025-03-04	KUPPUSAMY KARTHIK	Grant	4.4K	$173.74
2025-03-04	KUPPUSAMY KARTHIK	Tax withheld	1.9K	$173.74
2025-03-04	Plewman Patrick	Grant	5.7K	$173.74
2025-03-04	PREVOZNIK MICHAEL E	Sell	592	$175.79
2025-03-04	PREVOZNIK MICHAEL E	Grant	8.5K	$173.74
2025-03-04	PREVOZNIK MICHAEL E	Tax withheld	3.9K	$173.74
2025-03-04	DELANEY MARK E	Grant	5.3K	$173.74
2025-03-04	DELANEY MARK E	Tax withheld	1.8K	$173.74
2025-03-04	SAMAD SAM	Grant	14K	$173.74
2025-03-04	SAMAD SAM	Tax withheld	7.7K	$173.74
2025-03-03	Doherty Catherine T.	Tax withheld	394	$173.74
2025-03-03	PREVOZNIK MICHAEL E	Tax withheld	322	$173.74
2025-03-03	DEPPE MICHAEL J	Tax withheld	1.7K	$173.74
2025-03-03	Plewman Patrick	Tax withheld	106	$173.74
2025-03-03	KUPPUSAMY KARTHIK	Tax withheld	992	$173.74
2025-03-03	Davis J. E.	Tax withheld	1.7K	$173.74
2025-02-27	Doherty Catherine T.	Sell	824	$172.61
2025-02-27	PREVOZNIK MICHAEL E	Sell	528	$172.61
2025-02-26	PREVOZNIK MICHAEL E	Tax withheld	286	$171.75
2025-02-26	Plewman Patrick	Tax withheld	229	$171.75
2025-02-26	KUPPUSAMY KARTHIK	Tax withheld	233	$171.75
2025-02-26	Doherty Catherine T.	Tax withheld	455	$171.75
2025-02-26	SAMAD SAM	Tax withheld	869	$171.75
2025-02-26	DEPPE MICHAEL J	Tax withheld	88	$171.75
2025-02-26	DELANEY MARK E	Tax withheld	214	$171.75
2025-02-26	Davis J. E.	Tax withheld	3.0K	$171.75
2025-02-20	PREVOZNIK MICHAEL E	Sell	604	$170.99
2025-02-20	Doherty Catherine T.	Sell	899	$170.99
2025-02-19	Davis J. E.	Tax withheld	2.9K	$169.71
2025-02-19	Plewman Patrick	Sell	320	$169.71
2025-02-19	KUPPUSAMY KARTHIK	Tax withheld	287	$169.71
2025-02-19	Doherty Catherine T.	Sell	535	$169.71
2025-02-19	DEPPE MICHAEL J	Tax withheld	99	$169.71
2025-02-19	SAMAD SAM	Tax withheld	1.0K	$169.71
2025-02-19	DELANEY MARK E	Tax withheld	242	$169.71
2025-02-19	PREVOZNIK MICHAEL E	Tax withheld	374	$169.71
2025-02-12	DELANEY MARK E	Grant	1.8K	—
2025-02-12	Davis J. E.	Grant	18K	—
2025-02-12	SAMAD SAM	Grant	4.5K	—
2025-02-12	PREVOZNIK MICHAEL E	Grant	2.3K	—
2025-02-12	Plewman Patrick	Grant	2.0K	—
2025-02-12	KUPPUSAMY KARTHIK	Grant	2.3K	—
2025-02-12	Doherty Catherine T.	Grant	3.5K	—
2025-02-12	DEPPE MICHAEL J	Grant	454	—
2025-02-05	DELANEY MARK E	Sell	403	$164.30
2025-02-05	Gregg Vicky B	Sell	1.2K	$164.57
2025-01-29	Gregg Vicky B	L	72	$158.04
2025-01-29	SAMAD SAM	L	35	$158.04
2025-01-29	KUPPUSAMY KARTHIK	L	12	$158.03
2025-01-29	DELANEY MARK E	L	4	$158.03
2025-01-29	Plewman Patrick	L	57	$158.04

All non-derivative Form 4 activity (SEC), newest first.

Clinical trials

Trial	Title	Phase	Status	Primary completion
NCT04935138 ↗	Cell-free DNA Analysis of Chromosome Anomalies in Early Pregnancy Loss Early Pregnancy Loss	—	Terminated	2022-12-31

Source: ClinicalTrials.gov (U.S. NIH) · active studies first.

Supply chain

Customers (2)

Suppliers (0)

Named in the 10-K; linked when we track them.

Notable events (8-K)

Date	Items
2026-05-21	Shareholder vote	filing ↗
2026-05-08	Material agreementExhibits	filing ↗
2026-05-01	OtherExhibits	filing ↗
2026-04-21	ResultsExhibits	filing ↗
2026-03-12	Exec/director changeReg FDExhibits	filing ↗
2026-02-10	ResultsOtherExhibits	filing ↗
2026-01-12	ResultsReg FDExhibits	filing ↗
2025-10-21	ResultsExhibits	filing ↗

Recent filings

Form	Filed	Period	Accession
8-K	2026-05-21	2026-05-20	0001022079-26-000052 ↗
8-K	2026-05-08	2026-05-06	0001104659-26-057938 ↗
8-K	2026-05-01	2026-04-27	0001104659-26-054141 ↗
10-Q	2026-04-22	2026-03-31	0001022079-26-000043 ↗
8-K	2026-04-21	2026-04-21	0001022079-26-000040 ↗
8-K	2026-03-12	2026-03-09	0000947871-26-000244 ↗
10-K	2026-02-26	2025-12-31	0001022079-26-000015 ↗
8-K	2026-02-10	2026-02-10	0001022079-26-000005 ↗
8-K	2026-01-12	2026-01-12	0000947871-26-000025 ↗
8-K	2025-10-21	2025-10-21	0001022079-25-000219 ↗
10-Q	2025-10-21	2025-09-30	0001022079-25-000218 ↗
10-Q	2025-07-23	2025-06-30	0001022079-25-000175 ↗