Palo Alto Investors LP
In its 13F for Q1 2024 (holdings as of March 31, 2024, filed May 15, 2024), Palo Alto Investors LP reported 38 stock positions worth $886.7 million. Its top holding was Insmed (INSM) at 13.5% of the portfolio, followed by Amicus Therapeutics (FOLD, 12.4%) and Biomarin Pharmaceutical (BMRN, 11.2%). Compared with Q4 2023, it opened 6 new positions, sold out of 2, added to 12 and reduced 9. The biggest buy was Staar Surgical (STAA, shares +0%) and the biggest sale Biomarin Pharmaceutical (BMRN, shares −24%).
- Most Recent 13F
- Q2 2026
- Location
- PALO ALTO, CA
- CIK
- 0001306923
- Portfolio Value
- $886.7M (Q1 2024)
- SEC Filing
- 0001306923-24-000008 ↗ filed May 15, 2024
Holdings Value
Holdings 38 stocks · $886.7M
| INSM Insmed Inc. | 13.53% | 4,423,369 | $120.0M | Reduce -19.8% |
| FOLD Amicus Therapeutics Inc. | 12.41% | 9,344,102 | $110.1M | Reduce -9.9% |
| BMRN Biomarin Pharmaceutical Inc. | 11.18% | 1,134,569 | $99.1M | Reduce -24.4% |
| BIIB Biogen Inc. | 7.05% | 289,958 | $62.5M | Reduce -23.8% |
| UTHR United Therapeutics Corp. | 6.94% | 267,759 | $61.5M | Reduce -32.4% |
| STAA Staar Surgical Co. | 5.96% | 1,379,590 | $52.8M | Add +0.2% |
| ACAD Acadia Pharmaceuticals Inc. | 5.04% | 2,414,943 | $44.7M | Add +0.2% |
| PRTA Prothena Corp. PLC | 4.65% | 1,663,448 | $41.2M | Add +0.2% |
| IOVA Iovance Biotherapeutics Inc. | 3.53% | 2,112,811 | $31.3M | Add +0.3% |
| ALNY Alnylam Pharmaceuticals Inc. | 3.08% | 182,766 | $27.3M | Add +18.3% |
| SRPT Sarepta Therapeutics Inc. | 2.94% | 201,265 | $26.1M | Add +0.2% |
| RVNC Revance Therapeutics Inc. | 2.91% | 5,248,004 | $25.8M | Add +0.2% |
| SAGE Sage Therapeutics Inc. | 2.13% | 1,005,776 | $18.8M | Add +1.4% |
| ANAB Anaptysbio Inc. | 2.03% | 799,906 | $18.0M | Add +16.4% |
| EHTH Ehealth Inc. | 1.85% | 2,715,681 | $16.4M | Reduce -0.9% |
| ALGN Align Technology Inc. | 1.82% | 49,105 | $16.1M | Reduce -11.8% |
| ALKS Alkermes PLC | 1.51% | 495,592 | $13.4M | Reduce -17.9% |
| SLRN Acelyrin Inc. | 1.31% | 1,715,180 | $11.6M | New |
| NVRO Nevro LLC filed as NEVRO CORP | 1.22% | 750,371 | $10.8M | No change |
| SNDX Syndax Pharmaceuticals Inc. | 1.09% | 405,193 | $9.6M | Reduce -14.3% |
| NVCR Novocure Ltd. | 0.99% | 561,908 | $8.8M | No change |
| CYTK Cytokinetics Inc. | 0.88% | 111,717 | $7.8M | No change |
| KPTI Karyopharm Therapeutics Inc. | 0.87% | 5,102,193 | $7.7M | No change |
| VERV Verve Therapeutics Inc. | 0.86% | 575,817 | $7.6M | No change |
| GOSS Gossamer Bio Inc. | 0.85% | 6,391,775 | $7.5M | Add +7.3% |
| ELEV Elevation Oncology Inc. | 0.78% | 1,346,666 | $6.9M | New |
| BLUEBIRD BIO INC | 0.66% | 4,560,171 | $5.8M | Add +36.8% |
| RLMD Relmada Therapeutics Inc. | 0.38% | 732,400 | $3.4M | No change |
| NUVB Nuvation Bio Inc. | 0.32% | 772,652 | $2.8M | New |
| TSHA Taysha Gene Therapies Inc. | 0.26% | 811,268 | $2.3M | Add +53.1% |
| STOK Stoke Therapeutics Inc. | 0.19% | 125,861 | $1.7M | New |
| MIRM Mirum Pharmaceuticals Inc. | 0.18% | 64,700 | $1.6M | No change |
| HUM Humana Inc. | 0.16% | 3,985 | $1.4M | New |
| VYNE THERAPEUTICS INC | 0.15% | 445,434 | $1.4M | No change |
| TVTX Travere Therapeutics Inc. | 0.10% | 110,719 | $854K | No change |
| ALDX Aldeyra Therapeutics Inc. | 0.08% | 225,465 | $737K | No change |
| ACRS Aclaris Therapeutics Inc. | 0.08% | 569,832 | $707K | New |
| URGN Urogen Pharma Ltd. | 0.04% | 24,500 | $368K | No change |
Portfolio Sells Q4 2023 → Q1 2024
| BMRN Biomarin Pharmaceutical Inc. | Reduce -24.4% | 11.18% | −1.86 |
| INSM Insmed Inc. | Reduce -19.8% | 13.53% | −1.86 |
| BIIB Biogen Inc. | Reduce -23.8% | 7.05% | −1.82 |
| UTHR United Therapeutics Corp. | Reduce -32.4% | 6.94% | −0.90 |
| FOLD Amicus Therapeutics Inc. | Reduce -9.9% | 12.41% | −0.85 |
| EHTH Ehealth Inc. | Reduce -0.9% | 1.85% | −0.31 |
| VNDA Vanda Pharmaceuticals Inc. | Sold out | 0.00% | −0.11 |
| SGHT Sight Sciences Inc. | Sold out | 0.00% | −0.08 |
| ALKS Alkermes PLC | Reduce -17.9% | 1.51% | +0.00 |
| SNDX Syndax Pharmaceuticals Inc. | Reduce -14.3% | 1.09% | +0.17 |
| ALGN Align Technology Inc. | Reduce -11.8% | 1.82% | +0.44 |
Portfolio Buys Q4 2023 → Q1 2024
| STAA Staar Surgical Co. | Add +0.2% | 5.96% | +2.08 |
| IOVA Iovance Biotherapeutics Inc. | Add +0.3% | 3.53% | +1.99 |
| SLRN Acelyrin Inc. | New | 1.31% | +1.31 |
| SRPT Sarepta Therapeutics Inc. | Add +0.2% | 2.94% | +1.19 |
| ELEV Elevation Oncology Inc. | New | 0.78% | +0.78 |
| ANAB Anaptysbio Inc. | Add +16.4% | 2.03% | +0.71 |
| ALNY Alnylam Pharmaceuticals Inc. | Add +18.3% | 3.08% | +0.42 |
| NUVB Nuvation Bio Inc. | New | 0.32% | +0.32 |
| GOSS Gossamer Bio Inc. | Add +7.3% | 0.85% | +0.26 |
| BLUEBIRD BIO INC | Add +36.8% | 0.66% | +0.24 |
| STOK Stoke Therapeutics Inc. | New | 0.19% | +0.19 |
| SAGE Sage Therapeutics Inc. | Add +1.4% | 2.13% | +0.19 |
| TSHA Taysha Gene Therapies Inc. | Add +53.1% | 0.26% | +0.18 |
| HUM Humana Inc. | New | 0.16% | +0.16 |
| ACRS Aclaris Therapeutics Inc. | New | 0.08% | +0.08 |
| PRTA Prothena Corp. PLC | Add +0.2% | 4.65% | −0.79 |
| RVNC Revance Therapeutics Inc. | Add +0.2% | 2.91% | −1.24 |
| ACAD Acadia Pharmaceuticals Inc. | Add +0.2% | 5.04% | −1.76 |
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 |