Whale Analyzer
Top public holders · 13F and disclosure aggregation

Who owns MCO? 13F holders and whale ownership

MCO is tracked across public portfolios in Whale Analyzer. This page answers who owns MCO, which top funds are buying MCO, aggregate disclosed value, and recent position changes based on public data. Warren Buffett is the largest reported holder at $10.76B; the top five funds control 96.6% of reported ownership; institutions were net buying last quarter (5 increased, 2 reduced); the stock trades above the aggregate whale cost basis of $174.98. Top tracked holders include Warren Buffett, Chris Hohn, Dev Kantesaria, and Chuck Akre.

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NYQ · latest quote
$450.01
-$0.66 (-0.1%)
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10Tracked holders
$19.16BAggregate reported value
2026-05-21Page updated
4 increased, 3 held, 2 reduced, 1 newRecent changes

Top holders

InvestorReported valueSharesChange
Warren Buffett 13F portfolio
Berkshire Hathaway holdings
$10.76B24.7MHeld
Chris Hohn 13F portfolio
TCI Fund Management holdings
$6.25B14.3MIncreased
Dev Kantesaria 13F portfolio
Valley Forge Capital Management holdings
$574.6M1.3MReduced
Chuck Akre 13F portfolio
Akre Capital Management holdings
$543.6M1.2MReduced
Altarock Partners 13F portfolio
Altarock Partners holdings
$376.1M862.0KIncreased
Baillie Gifford 13F portfolio
Baillie Gifford & Co holdings
$333.4M764.3KIncreased
Al Gore / David Blood 13F portfolio
Generation Investment Management holdings
$159.8M366.4KIncreased
Tom Gayner 13F portfolio
Markel Group holdings
$93.3M213.9KHeld
Li Lu 13F portfolio
Himalaya Capital Management holdings
$51.4M117.8KNew
Guy Spier 13F portfolio
Aquamarine Fund holdings
$11.8M27.0KHeld

Ownership concentration

Reported ownership of MCO is highly concentrated across tracked institutions.

Whale activity this quarter

Across 10 tracked institutions, 5 increased, 3 held, 2 reduced. Net positioning is net buying.

Whale cost basis vs current price

The aggregate tracked cost basis is $174.98 versus a current price of $450.01, so MCO trades above its cost basis (+157.2%). Average unrealized P&L across tracked holders: 146%.

Sector positioning — Other

MCO sits within the Other sector alongside 670 other tracked names. Compare whale ownership across peers:

How to use this page

Values are reported public positions from tracked 13F filers and disclosures — not real-time ownership totals. Open the live MCO dashboard for price charts and cross-investor scans, or read the SEC 13F guide.

This page is generated from public filings and public disclosures. It is for research and education only and is not investment advice.

Related stock holder pages

Learn more in Whale Analyzer Academy

Deepen your read on MCO with these Whale Analyzer Academy guides:

Frequently asked questions

Who owns MCO stock?

Whale Analyzer tracks 10 public institutional holders of MCO with a combined reported value of $19.16B. See the holder table above for the largest tracked positions.

Which top funds are buying MCO?

Tracked institutions were net buying last quarter — 5 increased, 3 held, 2 reduced. Check the "Change" column: "New" = fresh position, "Increased" = added, "Reduced" = trimmed.

How concentrated is MCO ownership?

The top five tracked holders report 96.6% of aggregate ownership.

Is MCO above or below the whale cost basis?

The aggregate tracked cost basis is $174.98 versus a current price of $450.01 (+157.2%).

What does 13F ownership mean for MCO?

Use the interactive MCO dashboard on Whale Analyzer for real-time holder analysis, or read our 13F Alpha Signals Guide.