Whale Analyzer
TMO Institutional Holders and 13F Ownership
Compare 10 tracked holders of TMO, their reported positions and disclosed changes. Coverage is limited to the investors tracked by Whale Analyzer; these records do not establish all shareholders or current trades. Capital Group is the largest reported holder at $2.08B; the top five funds control 87.9% of reported ownership; institutions were net buying last quarter (7 increased, 3 reduced); the stock trades above the aggregate whale cost basis of $388.71. Top tracked holders include Capital Group, Dodge & Cox, PRIMECAP Management, and Andreas Halvorsen.
Continue to the live TMO dashboardTop holders
| Investor | Reported value | Shares | Change | Report date |
|---|---|---|---|---|
| Capital Group 13F portfolio Capital Research Global Investors holdings | $2.08B | 4.1M | Reduced | 2026-06-30 |
| Dodge & Cox 13F portfolio Dodge & Cox holdings | $1.53B | 3.1M | Increased | 2026-06-30 |
| PRIMECAP Management 13F portfolio PRIMECAP Management Company holdings | $993.8M | 2.0M | Reduced | 2026-06-30 |
| Andreas Halvorsen 13F portfolio Viking Global Investors holdings | $971.3M | 1.9M | Increased | 2026-06-30 |
| NPS Korea 13F portfolio National Pension Service holdings | $422.1M | 841.9K | Increased | 2026-06-30 |
| Dan Sundheim 13F portfolio D1 Capital Partners holdings | $409.7M | 817.1K | Increased | 2026-06-30 |
| Baillie Gifford 13F portfolio Baillie Gifford & Co holdings | $323.7M | 645.6K | Reduced | 2026-06-30 |
| Samuel Isaly 13F portfolio OrbiMed Advisors holdings | $45.5M | 90.7K | Increased | 2026-06-30 |
| Tom Gayner 13F portfolio Markel Group holdings | $36.6M | 73.1K | Increased | 2026-06-30 |
| Stanley Druckenmiller 13F portfolio Duquesne Family Office holdings | $9.6M | 19.2K | New | 2026-06-30 |
Ownership concentration
Reported ownership of TMO is highly concentrated across tracked institutions.
- Single largest holder: 30.5% of reported ownership
- Top 5 holders: 87.9%
- Top 10 holders: 100.0%
Whale activity this quarter
Across 10 tracked institutions, 7 increased, 3 reduced. Net positioning is net buying.
- Capital Group — Capital Research Global Investors ($2.08B) (▼ 6.0% qoq shares)
- Dodge & Cox — Dodge & Cox ($1.53B) (▲ 11767.4% qoq shares) · avg cost $434.41
- PRIMECAP Management — PRIMECAP Management Company ($993.8M) (→ 0.0% qoq shares)
- Andreas Halvorsen — Viking Global Investors ($971.3M) (▲ 16.2% qoq shares) · avg cost $313.06
- NPS Korea — National Pension Service ($422.1M) (▲ 1.5% qoq shares) · avg cost $337.40
- Dan Sundheim — D1 Capital Partners ($409.7M) (▲ 12.7% qoq shares) · avg cost $438.34
- Baillie Gifford — Baillie Gifford & Co ($323.7M) (▼ 7.6% qoq shares)
- Samuel Isaly — OrbiMed Advisors ($45.5M) (▲ 95.1% qoq shares)
Whale cost basis vs current price
The aggregate tracked cost basis is $388.71 versus a current price of $609.82, so TMO trades above its cost basis (+56.9%). Average unrealized P&L across tracked holders: 54%.
Sector positioning — Health Care
TMO sits within the Health Care sector alongside 221 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 TMO dashboard for price charts and cross-investor scans, or read the SEC 13F guide.
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Learn more in Whale Analyzer Academy
Deepen your read on TMO with these Whale Analyzer Academy guides:
Frequently asked questions
Who owns TMO stock?
Whale Analyzer tracks 10 public institutional holders of TMO with a combined reported value of $6.82B. See the holder table above for the largest tracked positions.
Which top funds are buying TMO?
Tracked institutions were net buying last quarter — 7 increased, 3 reduced. Check the "Change" column: "New" = fresh position, "Increased" = added, "Reduced" = trimmed.
How concentrated is TMO ownership?
The top five tracked holders report 87.9% of aggregate ownership.
Is TMO above or below the whale cost basis?
The aggregate tracked cost basis is $388.71 versus a current price of $609.82 (+56.9%).
What does 13F ownership mean for TMO?
These are historical reported positions from tracked filers, not real-time ownership or a complete shareholder register. Use the interactive TMO dashboard to explore them, or read our 13F Alpha Signals Guide.