BAKER BROS. ADVISORS LP: RHYTHM PHARMACEUTICALS INC (RYTM): Quarterly 13F Position History
As of Q2 2026, BAKER BROS. ADVISORS LP reported 5,604,483 shares of RHYTHM PHARMACEUTICALS INC (RYTM), worth $622.3M and representing 3.1% of its 13F equity book. The position first appeared in Q4 2017 and has been disclosed across 35 13F-HR filings in Pactolio's tracked window.
- 5,604,483Shares Held (Latest Filing)
- $622.3MReported Market Value (Latest Filing)
- 3.1%Portfolio Weight (% of 13F Equity Book)
- 0Quarter-over-Quarter Share Change
- +$134.8MQuarter-over-Quarter Value Change
- 6,702,349Peak Reported Shares (Historical)
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 35 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q2 2026 | 5,604,483 | 0 | – | $622.3M | 3.1% | $111.0 |
| Q1 2026 | 5,604,483 | 0 | – | $487.4M | 2.8% | $87.0 |
| Q4 2025 | 5,604,483 | 0 | – | $599.9M | 3.5% | $107.0 |
| Q3 2025 | 5,604,483 | 0 | – | $566.0M | 4.1% | $101.0 |
| Q2 2025 | 5,604,483 | 0 | – | $354.1M | 3.4% | $63.2 |
| Q1 2025 | 5,604,483 | 479,766 | -7.9% | $296.9M | 3.3% | $53.0 |
| Q4 2024 | 6,084,249 | 314,117 | -4.9% | $340.6M | 3.6% | $56.0 |
| Q3 2024 | 6,398,366 | +1 | +0.0% | $335.2M | 3.5% | $52.4 |
| Q2 2024 | 6,398,365 | 0 | – | $262.7M | 3.4% | $41.1 |
| Q1 2024 | 6,398,365 | 0 | – | $277.2M | 3.5% | $43.3 |
| Q4 2023 | 6,398,365 | 303,984 | -4.5% | $294.1M | 3.3% | $46.0 |
| Q3 2023 | 6,702,349 | +204,082 | +3.1% | $153.7M | 0.9% | $22.9 |
| Q2 2023 | 6,498,267 | 0 | – | $107.2M | 0.6% | $16.5 |
| Q1 2023 | 6,498,267 | +143,659 | +2.3% | $115.9M | 0.6% | $17.8 |
| Q4 2022 | 6,354,608 | +291,906 | +4.8% | $185.0M | 1.1% | $29.1 |
| Q3 2022 | 6,062,702 | +1,937,640 | +47.0% | $148.5M | 1.0% | $24.5 |
| Q2 2022 | 4,125,062 | 0 | – | $17.1M | 0.1% | $4.2 |
| Q1 2022 | 4,125,062 | +261,823 | +6.8% | $47.5M | 0.3% | $11.5 |
| Q4 2021 | 3,863,239 | 0 | – | $38.6M | 0.2% | $10.0 |
| Q3 2021 | 3,863,239 | 0 | – | $50.5M | 0.2% | $13.1 |
| Q2 2021 | 3,863,239 | +383,366 | +11.0% | $75.6M | 0.3% | $19.6 |
| Q1 2021 | 3,479,873 | +1,165,000 | +50.3% | $74.0M | 0.3% | $21.3 |
| Q4 2020 | 2,314,873 | 156,282 | -6.3% | $68.8M | 0.3% | $29.7 |
| Q3 2020 | 2,471,155 | 228,900 | -8.5% | $53.5M | 0.2% | $21.7 |
| Q2 2020 | 2,700,055 | 8,145 | -0.3% | $60.2M | 0.3% | $22.3 |
| Q1 2020 | 2,708,200 | 0 | – | $41.2M | 0.3% | $15.2 |
| Q4 2019 | 2,708,200 | 0 | – | $62.2M | 0.3% | $23.0 |
| Q3 2019 | 2,708,200 | 0 | – | $58.5M | 0.4% | $21.6 |
| Q2 2019 | 2,708,200 | 0 | – | $59.6M | 0.4% | $22.0 |
| Q1 2019 | 2,708,200 | 0 | – | $74.2M | 0.5% | $27.4 |
| Q4 2018 | 2,708,200 | 0 | – | $72.8M | 0.6% | $26.9 |
| Q3 2018 | 2,708,200 | 0 | – | $79.0M | 0.5% | $29.2 |
| Q2 2018 | 2,708,200 | +659,180 | +32.2% | $84.7M | 0.6% | $31.3 |
| Q1 2018 | 2,049,020 | 0 | – | $40.8M | 0.3% | $19.9 |
| Q4 2017 | 2,049,020 | – | – | $59.5M | 0.5% | $29.1 |
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 rather than the manager's cost basis. See the full methodology document for the normalization rules.
When did BAKER BROS. ADVISORS LP first disclose a RYTM position in 13F-HR filings?
BAKER BROS. ADVISORS LP first reported RHYTHM PHARMACEUTICALS INC (RYTM) on its 13F-HR filing for the period ending 2017-12-31 (Q4 2017). The position has appeared on 35 reported quarters within Pactolio's tracked window.
What was BAKER BROS. ADVISORS LP's most recent quarter-over-quarter share-count change in RYTM?
BAKER BROS. ADVISORS LP held the same 5,604,483 shares of RYTM between Q1 2026 and Q2 2026, so the reported share count was unchanged quarter-over-quarter.
Does the implied price-per-share represent BAKER BROS. ADVISORS LP's cost basis in RYTM?
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.