# Palo Alto Investors LP

> Institutional holdings reported to the SEC as of Q2 2026 on Form 13F. CIK 1306923. Source: https://holderbook.com/funds/1306923-palo-alto-investors-lp/

- Reported value: $2.2B
- Positions: 54
- Weight of the ten largest: 56.1%
- Filed: 2026-08-17

A 13F reports long US equity positions only. Short positions, bonds, foreign listings, private holdings and cash are not visible, so this is not the manager's whole book.

## Holdings

| Security | Ticker | Value | Shares | Weight | Quarters held |
|---|---|---|---|---|---|
| PTC THERAPEUTICS INC | [PTCT](https://holderbook.com/stocks/PTCT/) | $224.9M | 2,756,538 | 10.4% | 8 |
| ACADIA PHARMACEUTICALS INC | [ACAD](https://holderbook.com/stocks/ACAD/) | $144.9M | 5,728,192 | 6.7% | 31 |
| INSMED INC | [INSM](https://holderbook.com/stocks/INSM/) | $132.4M | 1,241,940 | 6.1% | 31 |
| ANAPTYSBIO INC | [ANAB](https://holderbook.com/stocks/ANAB/) | $122.2M | 1,810,467 | 5.6% | 24 |
| BIOMARIN PHARMACEUTICAL INC | [BMRN](https://holderbook.com/stocks/BMRN/) | $117.2M | 2,048,331 | 5.4% | 31 |
| DYNE THERAPEUTICS INC | [DYN](https://holderbook.com/stocks/DYN/) | $109.8M | 4,942,563 | 5.1% | 6 |
| UNITED THERAPEUTICS CORP DEL | [UTHR](https://holderbook.com/stocks/UTHR/) | $101.7M | 187,761 | 4.7% | 31 |
| DISC MEDICINE INC | [IRON](https://holderbook.com/stocks/IRON/) | $91.4M | 1,249,938 | 4.2% | 5 |
| BIOGEN INC | [BIIB](https://holderbook.com/stocks/BIIB/) | $90.9M | 420,837 | 4.2% | 23 |
| MIRUM PHARMACEUTICALS INC | - | $81.7M | 697,616 | 3.8% | 1 |
| ACADIA HEALTHCARE COMPANY IN | [ACHC](https://holderbook.com/stocks/ACHC/) | $72.5M | 2,864,096 | 3.3% | 1 |
| IOVANCE BIOTHERAPEUTICS INC | [IOVA](https://holderbook.com/stocks/IOVA/) | $66.1M | 15,888,627 | 3.0% | 11 |
| ULTRAGENYX PHARMACEUTICAL IN | [RARE](https://holderbook.com/stocks/RARE/) | $59.8M | 1,789,485 | 2.8% | 5 |
| NOVOCURE LTD | [NVCR](https://holderbook.com/stocks/NVCR/) | $58.2M | 3,841,317 | 2.7% | 14 |
| SYNDAX PHARMACEUTICALS INC | [SNDX](https://holderbook.com/stocks/SNDX/) | $56.7M | 2,594,958 | 2.6% | 26 |
| ANNEXON INC | [ANNX](https://holderbook.com/stocks/ANNX/) | $50.5M | 8,844,270 | 2.3% | 3 |
| BICARA THERAPEUTICS INC | [BCAX](https://holderbook.com/stocks/BCAX/) | $49.0M | 1,651,224 | 2.3% | 3 |
| CAREDX INC | [CDNA](https://holderbook.com/stocks/CDNA/) | $45.5M | 1,595,610 | 2.1% | 4 |
| CELLDEX THERAPEUTICS INC NEW | [CLDX](https://holderbook.com/stocks/CLDX/) | $44.6M | 1,199,568 | 2.1% | 2 |
| MIRUM PHARMACEUTICALS INC | [MIRM](https://holderbook.com/stocks/MIRM/) | $40.8M | 348,808 | 1.9% | 19 |
| COMPASS THERAPEUTICS INC | [CMPX](https://holderbook.com/stocks/CMPX/) | $38.3M | 17,495,439 | 1.8% | 3 |
| ALKERMES PLC | [ALKS](https://holderbook.com/stocks/ALKS/) | $38.1M | 727,680 | 1.8% | 23 |
| FIRST TRACKS BIOTHERAPEUTICS | [TRAX](https://holderbook.com/stocks/TRAX/) | $36.4M | 1,810,467 | 1.7% | 1 |
| PROTHENA CORP PLC | [PRTA](https://holderbook.com/stocks/PRTA/) | $33.6M | 3,429,465 | 1.5% | 31 |
| TRAVERE THERAPEUTICS INC | [TVTX](https://holderbook.com/stocks/TVTX/) | $28.6M | 502,575 | 1.3% | 23 |
| TAYSHA GENE THERAPIES INC | [TSHA](https://holderbook.com/stocks/TSHA/) | $28.4M | 4,174,146 | 1.3% | 11 |
| ACLARIS THERAPEUTICS INC | [ACRS](https://holderbook.com/stocks/ACRS/) | $25.6M | 4,840,290 | 1.2% | 10 |
| AGIOS PHARMACEUTICALS INC | [AGIO](https://holderbook.com/stocks/AGIO/) | $23.8M | 640,803 | 1.1% | 6 |
| CAPRICOR THERAPEUTICS INC | [CAPR](https://holderbook.com/stocks/CAPR/) | $16.6M | 689,289 | 0.8% | 3 |
| ALIGN TECHNOLOGY INC | [ALGN](https://holderbook.com/stocks/ALGN/) | $15.9M | 94,167 | 0.7% | 31 |
| ORUKA THERAPEUTICS INC | [ORKA](https://holderbook.com/stocks/ORKA/) | $9.6M | 100,638 | 0.4% | 4 |
| XENON PHARMACEUTICALS INC | [XENE](https://holderbook.com/stocks/XENE/) | $9.3M | 154,035 | 0.4% | 3 |
| NEUROCRINE BIOSCIENCES INC | [NBIX](https://holderbook.com/stocks/NBIX/) | $9.2M | 54,351 | 0.4% | 6 |
| EDWARDS LIFESCIENCES CORP | [EW](https://holderbook.com/stocks/EW/) | $9.1M | 100,920 | 0.4% | 8 |
| STOKE THERAPEUTICS INC | [STOK](https://holderbook.com/stocks/STOK/) | $8.3M | 253,893 | 0.4% | 10 |
| CYTOKINETICS INC | [CYTK](https://holderbook.com/stocks/CYTK/) | $8.2M | 96,585 | 0.4% | 2 |
| PYXIS ONCOLOGY INC | [PYXS](https://holderbook.com/stocks/PYXS/) | $7.8M | 2,592,831 | 0.4% | 8 |
| EHEALTH INC | [EHTH](https://holderbook.com/stocks/EHTH/) | $6.6M | 4,448,391 | 0.3% | 24 |
| CRISPR THERAPEUTICS AG | [CRSP](https://holderbook.com/stocks/CRSP/) | $6.5M | 118,815 | 0.3% | 5 |
| SAGIMET BIOSCIENCES INC | [SGMT](https://holderbook.com/stocks/SGMT/) | $5.8M | 750,000 | 0.3% | 1 |
| NUVATION BIO INC | [NUVB](https://holderbook.com/stocks/NUVB/) | $5.6M | 979,827 | 0.3% | 10 |
| BIONTECH SE | [BNTX](https://holderbook.com/stocks/BNTX/) | $5.5M | 58,842 | 0.3% | 8 |
| COMPASS PATHWAYS PLC | [CMPS](https://holderbook.com/stocks/CMPS/) | $4.9M | 346,848 | 0.2% | 3 |
| HUMANA INC | [HUM](https://holderbook.com/stocks/HUM/) | $4.7M | 11,955 | 0.2% | 10 |
| NEWAMSTERDAM PHARMA COMPANY | [NAMS](https://holderbook.com/stocks/NAMS/) | $4.5M | 133,077 | 0.2% | 1 |
| VERASTEM INC | [VSTM](https://holderbook.com/stocks/VSTM/) | $3.5M | 929,055 | 0.2% | 2 |
| MADRIGAL PHARMACEUTICALS INC | [MDGL](https://holderbook.com/stocks/MDGL/) | $2.9M | 5,361 | 0.1% | 2 |
| UROGEN PHARMA LTD | [URGN](https://holderbook.com/stocks/URGN/) | $2.7M | 73,500 | 0.1% | 26 |
| BICYCLE THERAPEUTICS PLC | [BCYC](https://holderbook.com/stocks/BCYC/) | $2.6M | 605,670 | 0.1% | 8 |
| XERIS BIOPHARMA HOLDINGS INC | [XERS](https://holderbook.com/stocks/XERS/) | $2.5M | 313,230 | 0.1% | 2 |
| ABEONA THERAPEUTICS INC | [ABEO](https://holderbook.com/stocks/ABEO/) | $2.0M | 326,595 | 0.1% | 8 |
| INSPIRE MED SYS INC | [INSP](https://holderbook.com/stocks/INSP/) | $1.2M | 26,316 | 0.1% | 3 |
| PROQR THRAPEUTICS N V | [PRQR](https://holderbook.com/stocks/PRQR/) | $1.1M | 566,421 | 0.0% | 4 |
| ALDEYRA THERAPEUTICS INC | [ALDX](https://holderbook.com/stocks/ALDX/) | $995.0K | 467,127 | 0.0% | 29 |

## What the disclosed book did

Not the fund's return. This is the change in value of the positions disclosed on Form 13F, had they been left untouched, against SPY over the same quarter ends.

| Quarter | Book | Market | Difference | Priced |
|---|---|---|---|---|
| Q2 2026 | +12.0% | +14.8% | -2.8% | 98% |
| Q1 2026 | -3.8% | -4.6% | +0.9% | 100% |
| Q4 2025 | +24.8% | +2.4% | +22.4% | 100% |
| Q3 2025 | +25.5% | +7.8% | +17.6% | 100% |
| Q2 2025 | -3.1% | +10.5% | -13.6% | 99% |
| Q1 2025 | -7.3% | -4.6% | -2.8% | 99% |
| Q4 2024 | -8.8% | +2.1% | -11.0% | 100% |
| Q3 2024 | -1.3% | +5.4% | -6.8% | 95% |

## Quarter by quarter

| Quarter | Value | Positions |
|---|---|---|
| Q2 2026 | $2.2B | 54 |
| Q1 2026 | $653.9M | 51 |
| Q4 2025 | $718.4M | 49 |
| Q3 2025 | $540.4M | 44 |
| Q2 2025 | $470.0M | 45 |
| Q1 2025 | $525.1M | 44 |
| Q4 2024 | $645.4M | 43 |
| Q3 2024 | $769.9M | 45 |
| Q2 2024 | $863.0M | 39 |
| Q1 2024 | $886.7M | 38 |
| Q4 2023 | $1.1B | 34 |
| Q3 2023 | $1.1B | 29 |