Route One Investment Company, L.P.: THERMO FISHER SCIENTIFIC INC (TMO): Quarterly 13F Position History
As of Q1 2026, Route One Investment Company, L.P. reported 258,700 shares of THERMO FISHER SCIENTIFIC INC (TMO), worth $127.2M and representing 5.6% of its 13F equity book. Quarter-over-quarter share count change: 4,900 (-1.9%) . The position first appeared in Q3 2023 and has been disclosed across 11 13F-HR filings in Pactolio's tracked window.
- 258,700Shares Held (Latest Filing)
- $127.2MReported Market Value (Latest Filing)
- 5.6%Portfolio Weight (% of 13F Equity Book)
- 4,900Quarter-over-Quarter Share Change
- -$25.6MQuarter-over-Quarter Value Change
- 293,380Peak Reported Shares (Historical)
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 11 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q1 2026 | 258,700 | 4,900 | -1.9% | $127.2M | 5.6% | $491.5 |
| Q4 2025 | 263,600 | 29,780 | -10.2% | $152.7M | 6.4% | $579.5 |
| Q3 2025 | 293,380 | 0 | — | $142.3M | 5.7% | $485.0 |
| Q2 2025 | 293,380 | +60,950 | +26.2% | $119.0M | 5.2% | $405.5 |
| Q1 2025 | 232,430 | 0 | — | $115.7M | 4.8% | $497.6 |
| Q4 2024 | 232,430 | +21,550 | +10.2% | $120.9M | 4.7% | $520.2 |
| Q3 2024 | 210,880 | 0 | — | $130.4M | 4.7% | $618.6 |
| Q2 2024 | 210,880 | 0 | — | $116.6M | 4.4% | $553.0 |
| Q1 2024 | 210,880 | 0 | — | $122.6M | 4.8% | $581.2 |
| Q4 2023 | 210,880 | +65,550 | +45.1% | $111.9M | 4.1% | $530.8 |
| Q3 2023 | 145,330 | — | — | $73.6M | 2.8% | $506.2 |
Methodology & FAQ
How This Position History Is Sourced
Each row is one SEC Form 13F-HR filing disclosing this position. Share count, market value, and reported quarter are taken verbatim from the filing; portfolio weight is recomputed against the same filing's total reported equity book. Implied price-per-share is market value divided by shares — a quarter-end mark, not the manager's cost basis. See the full methodology document for the normalization rules.
When did Route One Investment Company, L.P. first disclose a TMO position in 13F-HR filings?
Route One Investment Company, L.P. first reported THERMO FISHER SCIENTIFIC INC (TMO) on its 13F-HR filing for the period ending 2023-09-30 (Q3 2023). The position has appeared on 11 reported quarters within Pactolio's tracked window.
What was Route One Investment Company, L.P.'s most recent quarter-over-quarter share-count change in TMO?
Between Q4 2025 and Q1 2026, Route One Investment Company, L.P. reduced its TMO position by 4,900 shares (-1.9%), leaving 258,700 shares at a market value of $127.2M.
Does the implied price-per-share represent Route One Investment Company, L.P.'s cost basis in TMO?
No. The implied price-per-share column is the 13F-HR reported market value divided by reported share count on the filing date (end of quarter). It is a quarter-end mark, not a cost basis or transaction price. Use it as a sanity check on the value column, not as an indicator of the manager's entry or exit price.