THERMO FISHER SCIENTIFIC (TMO) Institutional Ownership & Top Holders
The most recent SEC Form 13F filings (Q2 2026) show 17 hedge funds and institutional investors holding a combined 7.8M shares of THERMO FISHER SCIENTIFIC (TMO), valued at $3.9B. The median portfolio weight is 1.2%.
Quarterly institutional ownership changes in TMO show net buying, with the combined position increasing by 4.4M shares (127.6%) from the previous quarter.
Among 13F filers, the funds with the highest portfolio allocation to TMO are Cryder (13.2% of its 13F portfolio), Lindsell Train (9.8%), and Route One Investment Company (5.8%). In Q2 2026, Viking Global made the largest position increase (+2.8%), while Tri Locum Partners made the largest reduction (-9.1%).
Top 10 Institutional Holders in THERMO FISHER SCIENTIFIC (TMO), Ranked by Portfolio Weight
Based on the latest SEC Form 13F filings (Q2 2026).
| # | Fund | Shares | Market Value | Portfolio Weight |
|---|---|---|---|---|
| 1 | Cryder | 419,181 | $210.2M | 13.2% |
| 2 | Lindsell Train | 514,512 | $258.0M | 9.8% |
| 3 | Route One Investment Company | 280,400 | $140.6M | 5.8% |
| 4 | Weitz Investment Management | 115,200 | $57.8M | 4.0% |
| 5 | Viking Global | 1,937,415 | $971.3M | 2.8% |
| 6 | Sound Shore Management | 165,318 | $82.9M | 2.6% |
| 7 | Senator | 100,000 | $50.1M | 1.8% |
| 8 | First Pacific Advisors | 248,244 | $124.5M | 1.5% |
| 9 | D1 Capital | 817,123 | $409.7M | 1.2% |
| 10 | Matrix Asset Advisors | 27,668 | $13.9M | 1.1% |
- 17Institutional investors
- 7,777,714Shares held (disclosed)
- $3.9B13F market value
- 1.2%Median portfolio weight
Ownership History
Quarter-by-quarter share count, market value, and portfolio conviction weight (up to 5 of the heaviest weight-by-portfolio funds) of TMO. Sourced from 13F filings; reflects long equity positions only.
Quarter-over-Quarter ActivityQ2 2026
The biggest weight-increase and weight-decrease changes among funds that hold TMO. Deltas compare the selected filing to the previous reporting quarter.
Top buyers
- Viking Global+2.8% · +1,937,415 shares
- Sound Shore Management+2.6% · +165,318 shares
- Senator+1.8% · +100,000 shares
Top sellers
- Tri Locum Partners-9.1% · -132,413 shares
- Cantillon Capital Management-2.5% · -769,698 shares
- MKP Capital-1.0% · -60,000 shares
Ownership Statistics
- Funds holding
- 17
- Median weight
- 1.2%
- Largest holder
- Cryder · 13.2%
- Smallest holder
- Mairs & Power · 0.0%
- Shares held
- 7,777,714 (+4,361,073)
All Institutional HoldersSortable · searchable
All institutional investors (Max 50) holding TMO in the selected quarter. Click a fund name to drill into its full 13F portfolio.
| 1 | Cryder | 419,181 | $210.2M | 13.2% |
| 2 | Lindsell Train | 514,512 | $258.0M | 9.8% |
| 3 | Route One Investment Company | 280,400 | $140.6M | 5.8% |
| 4 | Weitz Investment Management | 115,200 | $57.8M | 4.0% |
| 5 | Viking Global | 1,937,415 | $971.3M | 2.8% |
| 6 | Sound Shore Management | 165,318 | $82.9M | 2.6% |
| 7 | Senator | 100,000 | $50.1M | 1.8% |
| 8 | First Pacific Advisors | 248,244 | $124.5M | 1.5% |
| 9 | D1 Capital | 817,123 | $409.7M | 1.2% |
| 10 | Matrix Asset Advisors | 27,668 | $13.9M | 1.1% |
| 11 | Dodge & Cox | 3,054,778 | $1.5B | 0.8% |
| 12 | Markel Group | 73,100 | $36.6M | 0.3% |
| 13 | Hillman Capital Management | 750 | $376.0K | 0.3% |
| 14 | Duquesne Family Office | 19,200 | $9.6M | 0.2% |
| 15 | UTIMCO - The University of Texas | 2,769 | $1.4M | 0.2% |
| 16 | George Kaiser Family Foundation | 815 | $408.6K | 0.0% |
| 17 | Mairs & Power | 1,241 | $622.2K | 0.0% |
Institutional Investor Count Over Time
Number of institutional investors disclosing a long position in THERMO FISHER SCIENTIFIC INC (TMO) each reporting quarter. Sourced from SEC Form 13F-HR filings.
See THERMO FISHER SCIENTIFIC INC (TMO) insider transactions (SEC Form 4) →
Methodology & FAQ
Methodology: How We Track TMO Institutional Holdings
Our data is systematically aggregated directly from quarterly Form 13F-HR disclosures submitted to the U.S. Securities and Exchange Commission (SEC).
- Who must file: This dataset includes filings from U.S. institutional investment managers, hedge funds, mutual funds, university endowments, and family offices managing at least $100 million in Section 13(f) securities (including equities, options, convertibles, ETFs, and warrants).
- What is included: We capture long positions in Section 13(f) securities for THERMO FISHER SCIENTIFIC INC (TMO). By SEC regulation, 13F filings do not require the disclosure of short positions, non-U.S. holdings, or OTC derivatives. Listed options are excluded from portfolio weight calculations to ensure comparability across filers.
- Metric definition: “Portfolio Weight” shows how much of a fund's total reported 13F portfolio value (excluding listed options) is allocated to TMO on the specific reporting date.
- How to use this data: Quarter-over-quarter changes in shares and portfolio weight reflect a combination of active trading and market price movements. These are descriptive metrics of fund allocation, not explicit buy or sell signals.
How do you measure hedge fund conviction and institutional concentration in TMO?
We evaluate fund conviction by looking at portfolio weight rather than just absolute share count. By tracking how the largest holders , such as Cryder , Lindsell Train , and Route One Investment Company as of Q2 2026, change their position sizing quarter-over-quarter, we help investors distinguish between deliberate position sizing changes and passive mark-to-market drift.
Does the TMO ownership data include short interest or options?
SEC Form 13F mandates the disclosure of long positions in Section 13(f) securities, which includes equities and listed options (put and call contracts), but excludes short interest, swaps, and OTC derivatives by regulatory design. On this platform, listed options are excluded from portfolio weight calculations to ensure comparability across filers.
Are family offices and university endowments included in this TMO data?
Yes. In addition to traditional hedge funds and large asset managers, any institutional entity exercising investment discretion over at least $100 million in Section 13(f) securities must file a Form 13F. This explicitly includes single-family offices and university endowments. If a qualifying family office or endowment holds TMO stock, their allocation is systematically aggregated alongside traditional fund data.
When is the institutional ownership data updated, and is there a reporting lag?
Institutional investment managers are required to file their Form 13F within 45 days after the end of a calendar quarter (the standard “T+45” window). Our platform re-ingests new filings from the SEC EDGAR database on a nightly cycle, typically within 24–48 hours of publication, providing a point-in-time snapshot of reported consensus positioning for TMO as of each filing date.