Frazier Life Sciences Management, L.P.: MBX BIOSCIENCES INC (MBX): Quarterly 13F Position History
As of Q1 2026, Frazier Life Sciences Management, L.P. reported 6,652,013 shares of MBX BIOSCIENCES INC (MBX), worth $198.6M and representing 5.1% of its 13F equity book. The position first appeared in Q3 2024 and has been disclosed across 7 13F-HR filings in Pactolio's tracked window.
- 6,652,013Shares Held (Latest Filing)
- $198.6MReported Market Value (Latest Filing)
- 5.1%Portfolio Weight (% of 13F Equity Book)
- 0Quarter-over-Quarter Share Change
- -$11.2MQuarter-over-Quarter Value Change
- 6,652,013Peak Reported Shares (Historical)
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 7 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q1 2026 | 6,652,013 | 0 | — | $198.6M | 5.1% | $29.9 |
| Q4 2025 | 6,652,013 | 0 | — | $209.8M | 5.6% | $31.5 |
| Q3 2025 | 6,652,013 | +666,666 | +11.1% | $116.4M | 3.5% | $17.5 |
| Q2 2025 | 5,985,347 | 0 | — | $68.3M | 2.7% | $11.4 |
| Q1 2025 | 5,985,347 | 0 | — | $44.2M | 2.0% | $7.4 |
| Q4 2024 | 5,985,347 | 0 | — | $110.3M | 4.6% | $18.4 |
| Q3 2024 | 5,985,347 | — | — | $155.5M | 6.2% | $26.0 |
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 MBX position in 13F-HR filings?
Frazier Life Sciences Management, L.P. first reported MBX BIOSCIENCES INC (MBX) on its 13F-HR filing for the period ending 2024-09-30 (Q3 2024). The position has appeared on 7 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 MBX?
Frazier Life Sciences Management, L.P. held the same 6,652,013 shares of MBX 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 MBX?
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.