BAKER BROS. ADVISORS LP: ACADIA PHARMACEUTICALS INC. (ACAD): Quarterly 13F Position History
As of Q1 2026, BAKER BROS. ADVISORS LP reported 42,896,690 shares of ACADIA PHARMACEUTICALS INC. (ACAD), worth $954.9M and representing 5.5% of its 13F equity book. The position first appeared in Q1 2016 and has been disclosed across 41 13F-HR filings in Pactolio's tracked window.
- 42,896,690Shares Held (Latest Filing)
- $954.9MReported Market Value (Latest Filing)
- 5.5%Portfolio Weight (% of 13F Equity Book)
- 0Quarter-over-Quarter Share Change
- -$190.9MQuarter-over-Quarter Value Change
- 42,896,690Peak Reported Shares (Historical)
Quarterly 13F-HR Disclosure History Source: SEC 13F-HR filings, 41 quarter s
| Quarter | Shares | QoQ Share Change | Share Change (%) | Market Value | Weight | Implied Price |
|---|---|---|---|---|---|---|
| Q1 2026 | 42,896,690 | 0 | — | $954.9M | 5.5% | $22.3 |
| Q4 2025 | 42,896,690 | 0 | — | $1.1B | 6.7% | $26.7 |
| Q3 2025 | 42,896,690 | 0 | — | $915.4M | 6.6% | $21.3 |
| Q2 2025 | 42,896,690 | +18,774 | +0.0% | $925.3M | 9.0% | $21.6 |
| Q1 2025 | 42,877,916 | 0 | — | $712.2M | 7.9% | $16.6 |
| Q4 2024 | 42,877,916 | 0 | — | $786.8M | 8.4% | $18.4 |
| Q3 2024 | 42,877,916 | 0 | — | $659.5M | 6.8% | $15.4 |
| Q2 2024 | 42,877,916 | +13,304 | +0.0% | $696.8M | 8.9% | $16.3 |
| Q1 2024 | 42,864,612 | 0 | — | $792.6M | 9.9% | $18.5 |
| Q4 2023 | 42,864,612 | 0 | — | $1.3B | 15.3% | $31.3 |
| Q3 2023 | 42,864,612 | 0 | — | $893.3M | 5.1% | $20.8 |
| Q2 2023 | 42,864,612 | +926,126 | +2.2% | $1.0B | 5.9% | $23.9 |
| Q1 2023 | 41,938,486 | +15,000 | +0.0% | $789.3M | 4.3% | $18.8 |
| Q4 2022 | 41,923,486 | 0 | — | $667.4M | 4.0% | $15.9 |
| Q3 2022 | 41,923,486 | 0 | — | $685.9M | 4.5% | $16.4 |
| Q2 2022 | 41,923,486 | +12,782 | +0.0% | $590.7M | 3.4% | $14.1 |
| Q1 2022 | 41,910,704 | 0 | — | $1.0B | 5.8% | $24.2 |
| Q4 2021 | 41,910,704 | 0 | — | $978.2M | 4.8% | $23.3 |
| Q3 2021 | 41,910,704 | 0 | — | $696.1M | 3.1% | $16.6 |
| Q2 2021 | 41,910,704 | 0 | — | $1.0B | 4.5% | $24.4 |
| Q1 2021 | 41,910,704 | +6,118 | +0.0% | $1.1B | 4.7% | $25.8 |
| Q4 2020 | 41,904,586 | 0 | — | $2.2B | 8.4% | $53.5 |
| Q3 2020 | 41,904,586 | 0 | — | $1.7B | 6.9% | $41.3 |
| Q2 2020 | 41,904,586 | 0 | — | $2.0B | 9.0% | $48.5 |
| Q1 2020 | 41,904,586 | +1,050,000 | +2.6% | $1.8B | 10.9% | $42.3 |
| Q4 2019 | 40,854,586 | 0 | — | $1.7B | 9.3% | $42.8 |
| Q3 2019 | 40,854,586 | +1,562,500 | +4.0% | $1.5B | 10.0% | $36.0 |
| Q2 2019 | 39,292,086 | 421,756 | -1.1% | $1.1B | 7.1% | $26.7 |
| Q1 2019 | 39,713,842 | 0 | — | $1.1B | 6.8% | $26.9 |
| Q4 2018 | 39,713,842 | +11,274,728 | +39.6% | $642.2M | 5.3% | $16.2 |
| Q3 2018 | 28,439,114 | +1,210,776 | +4.4% | $590.4M | 3.9% | $20.8 |
| Q2 2018 | 27,228,338 | 0 | — | $415.8M | 3.1% | $15.3 |
| Q1 2018 | 27,228,338 | 0 | — | $611.8M | 5.2% | $22.5 |
| Q4 2017 | 27,228,338 | +1,408,570 | +5.5% | $819.8M | 7.1% | $30.1 |
| Q3 2017 | 25,819,768 | 0 | — | $972.6M | 7.9% | $37.7 |
| Q2 2017 | 25,819,768 | 0 | — | $720.1M | 6.3% | $27.9 |
| Q1 2017 | 25,819,768 | 0 | — | $887.7M | 7.3% | $34.4 |
| Q4 2016 | 25,819,768 | 0 | — | $744.6M | 7.3% | $28.8 |
| Q3 2016 | 25,819,768 | +1,303,030 | +5.3% | $821.3M | 7.5% | $31.8 |
| Q2 2016 | 24,516,738 | +302,900 | +1.3% | $795.8M | 8.3% | $32.5 |
| Q1 2016 | 24,213,838 | — | — | $677.0M | 7.1% | $28.0 |
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 BAKER BROS. ADVISORS LP first disclose a ACAD position in 13F-HR filings?
BAKER BROS. ADVISORS LP first reported ACADIA PHARMACEUTICALS INC. (ACAD) on its 13F-HR filing for the period ending 2016-03-31 (Q1 2016). The position has appeared on 41 reported quarters within Pactolio's tracked window.
What was BAKER BROS. ADVISORS LP's most recent quarter-over-quarter share-count change in ACAD?
BAKER BROS. ADVISORS LP held the same 42,896,690 shares of ACAD between Q4 2025 and Q1 2026 — the reported share count was unchanged quarter-over-quarter.
Does the implied price-per-share represent BAKER BROS. ADVISORS LP's cost basis in ACAD?
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.