Palo Alto Investors LP
In its 13F for Q2 2025 (holdings as of June 30, 2025, filed August 14, 2025), Palo Alto Investors LP reported 45 stock positions worth $470.0 million. Its top holding was Insmed (INSM) at 18.5% of the portfolio, followed by Acadia Pharmaceuticals (ACAD, 11.8%) and Biomarin Pharmaceutical (BMRN, 9.8%). Compared with Q1 2025, it opened 7 new positions, sold out of 6, added to 5 and reduced 15. The biggest buy was a new position in Disc Medicine (IRON) and the biggest sale Amicus Therapeutics (FOLD, shares −24%).
- Most Recent 13F
- Q2 2026
- Location
- PALO ALTO, CA
- CIK
- 0001306923
- Portfolio Value
- $470.0M (Q2 2025)
- SEC Filing
- 0001306923-25-000016 ↗ filed Aug 14, 2025
Holdings Value
Holdings 45 stocks · $470.0M
| INSM Insmed Inc. | 18.52% | 865,113 | $87.1M | Reduce -12.4% |
| ACAD Acadia Pharmaceuticals Inc. | 11.76% | 2,563,209 | $55.3M | Reduce -3.8% |
| BMRN Biomarin Pharmaceutical Inc. | 9.83% | 840,470 | $46.2M | Reduce -15.2% |
| FOLD Amicus Therapeutics Inc. | 6.84% | 5,610,513 | $32.1M | Reduce -23.6% |
| UTHR United Therapeutics Corp. | 5.84% | 95,482 | $27.4M | Reduce -9.3% |
| BIIB Biogen Inc. | 5.50% | 205,759 | $25.8M | Add +0.4% |
| ALNY Alnylam Pharmaceuticals Inc. | 5.24% | 75,535 | $24.6M | Reduce -9.5% |
| PTCT PTC Therapeutics Inc. | 4.22% | 406,469 | $19.9M | Add +0.6% |
| ANAB Anaptysbio Inc. | 3.84% | 812,821 | $18.0M | Reduce -20.4% |
| NVCR Novocure Ltd. | 3.64% | 962,396 | $17.1M | Reduce -4.0% |
| STAA Staar Surgical Co. | 2.83% | 791,879 | $13.3M | Add +50.8% |
| AGIO Agios Pharmaceuticals Inc. | 1.90% | 268,783 | $8.9M | Reduce -2.8% |
| PRTA Prothena Corp. PLC | 1.65% | 1,274,753 | $7.7M | Reduce -23.2% |
| IRON Disc Medicine Inc. | 1.64% | 145,691 | $7.7M | New |
| ALGN Align Technology Inc. | 1.52% | 37,772 | $7.2M | No change |
| GOSS Gossamer Bio Inc. | 1.50% | 5,739,013 | $7.1M | Reduce -8.6% |
| EHTH Ehealth Inc. | 1.46% | 1,577,850 | $6.9M | Reduce -6.3% |
| ALKS Alkermes PLC | 1.35% | 221,021 | $6.3M | Reduce -0.2% |
| IOVA Iovance Biotherapeutics Inc. | 1.25% | 3,429,329 | $5.9M | Add +6.8% |
| SNDX Syndax Pharmaceuticals Inc. | 0.89% | 444,367 | $4.2M | No change |
| RNAM Avidity Biosciences Inc. | 0.72% | 118,886 | $3.4M | New |
| DNLI Denali Therapeutics Inc. | 0.71% | 239,809 | $3.4M | New |
| MIRM Mirum Pharmaceuticals Inc. | 0.70% | 64,700 | $3.3M | No change |
| EW Edwards Lifesciences Corp. | 0.66% | 39,473 | $3.1M | No change |
| TSHA Taysha Gene Therapies Inc. | 0.61% | 1,246,033 | $2.9M | Reduce -12.2% |
| BNTX Biontech SE-ADR | 0.57% | 25,206 | $2.7M | No change |
| DYN Dyne Therapeutics Inc. | 0.54% | 264,976 | $2.5M | Reduce -20.5% |
| CRSP Crispr Therapeutics AG | 0.46% | 44,625 | $2.2M | New |
| ACRS Aclaris Therapeutics Inc. | 0.42% | 1,390,028 | $2.0M | Add +79.1% |
| RARE Ultragenyx Pharmaceutical Inc. | 0.38% | 48,750 | $1.8M | New |
| BCYC Bicycle Therapeutics PLC-ADR | 0.37% | 248,934 | $1.7M | No change |
| NBIX Neurocrine Biosciences Inc. | 0.36% | 13,334 | $1.7M | No change |
| TVTX Travere Therapeutics Inc. | 0.35% | 110,719 | $1.6M | No change |
| NUVB Nuvation Bio Inc. | 0.32% | 772,652 | $1.5M | No change |
| STOK Stoke Therapeutics Inc. | 0.30% | 125,861 | $1.4M | No change |
| PYXS Pyxis Oncology Inc. | 0.24% | 1,037,421 | $1.1M | No change |
| HUM Humana Inc. | 0.21% | 3,985 | $974K | No change |
| ALDX Aldeyra Therapeutics Inc. | 0.18% | 225,465 | $864K | No change |
| KPTI Karyopharm Therapeutics Inc. | 0.17% | 187,911 | $810K | New |
| VYNE THERAPEUTICS INC | 0.16% | 445,434 | $735K | No change |
| ABEO Abeona Therapeutics Inc. | 0.13% | 108,865 | $618K | No change |
| ALMS Alumis Inc. | 0.09% | 143,437 | $430K | New |
| URGN Urogen Pharma Ltd. | 0.07% | 24,500 | $336K | No change |
| AKTX Akari Therapeutics PLC | 0.04% | 146,024 | $171K | No change |
| GBIO Generation Bio Co. | 0.01% | 150,475 | $48K | No change |
Portfolio Sells Q1 2025 → Q2 2025
| FOLD Amicus Therapeutics Inc. | Reduce -23.6% | 6.84% | −4.57 |
| BMRN Biomarin Pharmaceutical Inc. | Reduce -15.2% | 9.83% | −3.51 |
| SRPT Sarepta Therapeutics Inc. | Sold out | 0.00% | −2.56 |
| PRTA Prothena Corp. PLC | Reduce -23.2% | 1.65% | −2.26 |
| SLRN Acelyrin Inc. | Sold out | 0.00% | −0.84 |
| EHTH Ehealth Inc. | Reduce -6.3% | 1.46% | −0.68 |
| VERV Verve Therapeutics Inc. | Sold out | 0.00% | −0.50 |
| UTHR United Therapeutics Corp. | Reduce -9.3% | 5.84% | −0.34 |
| KPTI Karyopharm Therapeutics Inc. | Sold out | 0.00% | −0.23 |
| DYN Dyne Therapeutics Inc. | Reduce -20.5% | 0.54% | −0.13 |
| ALKS Alkermes PLC | Reduce -0.2% | 1.35% | −0.05 |
| TIL Instil Bio Inc. | Sold out | 0.00% | −0.04 |
| RLMD Relmada Therapeutics Inc. | Sold out | 0.00% | −0.03 |
| GOSS Gossamer Bio Inc. | Reduce -8.6% | 1.50% | +0.19 |
| ANAB Anaptysbio Inc. | Reduce -20.4% | 3.84% | +0.23 |
| TSHA Taysha Gene Therapies Inc. | Reduce -12.2% | 0.61% | +0.24 |
| NVCR Novocure Ltd. | Reduce -4.0% | 3.64% | +0.24 |
| AGIO Agios Pharmaceuticals Inc. | Reduce -2.8% | 1.90% | +0.36 |
| ALNY Alnylam Pharmaceuticals Inc. | Reduce -9.5% | 5.24% | +0.95 |
| ACAD Acadia Pharmaceuticals Inc. | Reduce -3.8% | 11.76% | +3.34 |
| INSM Insmed Inc. | Reduce -12.4% | 18.52% | +4.18 |
Portfolio Buys Q1 2025 → Q2 2025
| IRON Disc Medicine Inc. | New | 1.64% | +1.64 |
| STAA Staar Surgical Co. | Add +50.8% | 2.83% | +1.06 |
| RNAM Avidity Biosciences Inc. | New | 0.72% | +0.72 |
| DNLI Denali Therapeutics Inc. | New | 0.71% | +0.71 |
| CRSP Crispr Therapeutics AG | New | 0.46% | +0.46 |
| RARE Ultragenyx Pharmaceutical Inc. | New | 0.38% | +0.38 |
| PTCT PTC Therapeutics Inc. | Add +0.6% | 4.22% | +0.30 |
| ACRS Aclaris Therapeutics Inc. | Add +79.1% | 0.42% | +0.19 |
| KPTI Karyopharm Therapeutics Inc. | New | 0.17% | +0.17 |
| BIIB Biogen Inc. | Add +0.4% | 5.50% | +0.16 |
| ALMS Alumis Inc. | New | 0.09% | +0.09 |
| IOVA Iovance Biotherapeutics Inc. | Add +6.8% | 1.25% | −0.78 |
All Filings
| Quarter | Positions | 13F Reported Value | Top Holdings |
|---|---|---|---|
| Q2 2026Amended | 52 | $723.7M | PTCT, ACAD, INSM, MIRM, ANAB |
| Q1 2026 | 51 | $653.9M | INSM, ACAD, PTCT, BMRN, UTHR |
| Q4 2025 | 49 | $718.4M | INSM, FOLD, PTCT, ACAD, BMRN |
| Q3 2025 | 44 | $540.4M | INSM, PTCT, ACAD, FOLD, BMRN |
| Q2 2025 | 45 | $470.0M | INSM, ACAD, BMRN, FOLD, UTHR |
| Q1 2025 | 44 | $525.1M | INSM, BMRN, FOLD, ACAD, UTHR |
| Q4 2024 | 43 | $645.4M | INSM, FOLD, BMRN, UTHR, ACAD |
| Q3 2024 | 45 | $769.9M | INSM, FOLD, BMRN, UTHR, BIIB |
| Q2 2024 | 39 | $863.0M | INSM, BMRN, FOLD, UTHR, BIIB |
| Q1 2024 | 38 | $886.7M | INSM, FOLD, BMRN, BIIB, UTHR |