Frazier Life Sciences Management, L.P.: PHATHOM PHARMACEUTICALS INC (PHAT): Quarterly 13F Position History
As of Q1 2026, Frazier Life Sciences Management, L.P. reported 12,466,489 shares of PHATHOM PHARMACEUTICALS INC (PHAT), worth $138.5M and representing 3.6% of its 13F equity book. The position first appeared in Q1 2022 and has been disclosed across 17 13F-HR filings in Pactolio's tracked window.
- 12,466,489Shares Held (Latest Filing)
- $138.5MReported Market Value (Latest Filing)
- 3.6%Portfolio Weight (% of 13F Equity Book)
- 0Quarter-over-Quarter Share Change
- -$68.3MQuarter-over-Quarter Value Change
- 12,466,489Peak Reported Shares (Historical)
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 17 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q1 2026 | 12,466,489 | 0 | — | $138.5M | 3.6% | $11.1 |
| Q4 2025 | 12,466,489 | 0 | — | $206.8M | 5.6% | $16.6 |
| Q3 2025 | 12,466,489 | 0 | — | $146.7M | 4.4% | $11.8 |
| Q2 2025 | 12,466,489 | +2,357,210 | +23.3% | $119.6M | 4.8% | $9.6 |
| Q1 2025 | 10,109,279 | 0 | — | $63.4M | 2.9% | $6.3 |
| Q4 2024 | 10,109,279 | 0 | — | $82.1M | 3.4% | $8.1 |
| Q3 2024 | 10,109,279 | 0 | — | $182.8M | 7.3% | $18.1 |
| Q2 2024 | 10,109,279 | 0 | — | $104.1M | 4.9% | $10.3 |
| Q1 2024 | 10,109,279 | 0 | — | $107.4M | 4.5% | $10.6 |
| Q4 2023 | 10,109,279 | 0 | — | $92.3M | 4.9% | $9.1 |
| Q3 2023 | 10,109,279 | 0 | — | $104.8M | 7.0% | $10.4 |
| Q2 2023 | 10,109,279 | +1,702,127 | +20.2% | $144.8M | 8.6% | $14.3 |
| Q1 2023 | 8,407,152 | 0 | — | $60.0M | 4.3% | $7.1 |
| Q4 2022 | 8,407,152 | 0 | — | $94.3M | 5.9% | $11.2 |
| Q3 2022 | 8,407,152 | +2,579,737 | +44.3% | $93.2M | 7.2% | $11.1 |
| Q2 2022 | 5,827,415 | 0 | — | $49.2M | 4.6% | $8.4 |
| Q1 2022 | 5,827,415 | — | — | $79.3M | 6.8% | $13.6 |
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 Frazier Life Sciences Management, L.P. first disclose a PHAT position in 13F-HR filings?
Frazier Life Sciences Management, L.P. first reported PHATHOM PHARMACEUTICALS INC (PHAT) on its 13F-HR filing for the period ending 2022-03-31 (Q1 2022). The position has appeared on 17 reported quarters within Pactolio's tracked window.
What was Frazier Life Sciences Management, L.P.'s most recent quarter-over-quarter share-count change in PHAT?
Frazier Life Sciences Management, L.P. held the same 12,466,489 shares of PHAT between Q4 2025 and Q1 2026 — the reported share count was unchanged quarter-over-quarter.
Does the implied price-per-share represent Frazier Life Sciences Management, L.P.'s cost basis in PHAT?
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.