DGX

Quest Diagnostics COMMON

14 superinvestors own DGX

Based on latest 13F filings — data is 45–90 days delayed

Investor	Fund	Weight	Shares	Value	Quarter	Activity
Viking Global Investors	Viking Global Investors	2.22%	1,513,400	$78.2M	2008Q3	New
Valley Forge Capital Management	Valley Forge Capital Management	1.90%	128,803	$7.5M	2010Q1	Added
William Von Mueffling	Cantillon Capital Management	1.76%	1,148,920	$68.8M	2006Q2	Held
Alex Roepers	Atlantic Investment Management	1.61%	275,000	$13.7M	2010Q2	New
Robert Olstein	Olstein Capital Management	1.53%	35,800	$7K	2026Q1	Reduced
Christopher Davis	Davis Selected Advisers	1.46%	1,617,813	$317.1M	2026Q1	Added
Sarah Ketterer	Causeway Capital Management	0.43%	120,400	$20.4M	2025Q1	Reduced
Bill Nygren	Oakmark Select Fund – Harris Associates	0.41%	4,268,300	$228.5M	2013Q4	Held
Jensen Investment Management	Jensen Investment Management	0.01%	8,070	$490K	2014Q3	Reduced
Lee Ainslie	Maverick Capital	0.01%	2,756	$540K	2026Q1	Reduced
Meridian / ArrowMark	Meridian Contrarian Fund	0.01%	3,300	$204K	2013Q3	New
Kenneth Fisher	Fisher Asset Management	0.00%	1,269	$220K	2025Q4	Added
Richard Pzena	Pzena Investment Management	0.00%	1,966	$241K	2022Q3	Held
First Eagle Investment Management	First Eagle Investment Management	0.00%	3,000	$588K	2026Q1	Reduced

Open-market purchases (P) and sales (S) from SEC Form 4 filings · last 12 months

No open-market insider trades in the last 12 months.

Form 4 filings for option exercises and other transaction types are excluded.

STOCK Act disclosures · last 12 months

Congressional trade data coming soon.

We are sourcing STOCK Act disclosures and will display them here shortly.

What Is SEC Form 4?

Understand the insider trade filings behind DGX activity.

What Is a 13F Filing?

How superinvestors disclose their quarterly holdings.

Insider Cluster Buying

Why multiple insiders buying together is a strong signal.

Superinvestor Consensus

The most widely held stocks across all tracked institutions.