Palo Alto Investors LP — 13F Holdings & Portfolio
CIK 1306923 · latest 13F-HR filed 2026-08-19
Palo Alto Investors LP manages $723.7M in 13F-reported U.S. long-equity assets across 52 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are PTCT (10.36%), ACAD (10.01%), INSM (6.10%). Quarter over quarter (versus its 2026-06-30 filing) the fund opened 1 new position, exited 1, added to 0, and trimmed 0.
AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.
SUITE 200
PALO ALTO, CA 94301
$723.7M
Long-equity book
52
Distinct positions
2026-06-30
Filed 2026-08-19
+1 / −1 / ↑0 / ↓0
vs 2026-06-30
| Name | Title / Status | Ownership | Type |
|---|
Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).
| # | Issuer | Symbol | CUSIP | Value | Weight | Shares | Type |
|---|---|---|---|---|---|---|---|
| 1 | PTC THERAPEUTICS INC | PTCT | 69366J200 | $75.0M | 10.36% | 918,846 | SH |
| 2 | ACADIA PHARMACEUTICALS INC | ACAD | 004225108 | $72.5M | 10.01% | 2,864,096 | SH |
| 3 | INSMED INC | INSM | 457669307 | $44.1M | 6.10% | 413,980 | SH |
| 4 | MIRUM PHARMACEUTICALS INC | MIRM | 604749101 | $40.8M | 5.64% | 348,808 | SH |
| 5 | ANAPTYSBIO INC | ANAB | 032724106 | $40.7M | 5.63% | 603,489 | SH |
| 6 | BIOMARIN PHARMACEUTICAL INC | BMRN | 09061G101 | $39.1M | 5.40% | 682,777 | SH |
| 7 | DYNE THERAPEUTICS INC | DYN | 26818M108 | $36.6M | 5.06% | 1,647,521 | SH |
| 8 | UNITED THERAPEUTICS CORP | UTHR | 91307C102 | $33.9M | 4.69% | 62,587 | SH |
| 9 | DISC MEDICINE INC | IRON | 254604101 | $30.5M | 4.21% | 416,646 | SH |
| 10 | BIOGEN INC | BIIB | 09062X103 | $30.3M | 4.19% | 140,279 | SH |
| 11 | IOVANCE BIOTHERAPEUTICS INC | IOVA | 462260100 | $22.0M | 3.04% | 5,296,209 | SH |
| 12 | ULTRAGENYX PHARMACEUTICAL IN | RARE | 90400D108 | $19.9M | 2.75% | 596,495 | SH |
| 13 | NOVOCURE LTD | NVCR | G6674U108 | $19.4M | 2.68% | 1,280,439 | SH |
| 14 | SYNDAX PHARMACEUTICALS INC | SNDX | 87164F105 | $18.9M | 2.61% | 864,986 | SH |
| 15 | ANNEXON INC | ANNX | 03589W102 | $16.8M | 2.33% | 2,948,090 | SH |
| 16 | BICARA THERAPEUTICS INC | BCAX | 055477103 | $16.3M | 2.26% | 550,408 | SH |
| 17 | CAREDX INC | CDNA | 14167L103 | $15.2M | 2.09% | 531,870 | SH |
| 18 | CELLDEX THERAPEUTICS INC | CLDX | 15117B202 | $14.9M | 2.06% | 399,856 | SH |
| 19 | COMPASS THERAPEUTICS INC | CMPX | 20454B104 | $12.8M | 1.76% | 5,831,813 | SH |
| 20 | ALKERMES PLC | ALKS | G01767105 | $12.7M | 1.76% | 242,560 | SH |
| 21 | FIRST TRACKS BIOTHERAPEUTICS | TRAX | 337185102 | $12.1M | 1.68% | 603,489 | SH |
| 22 | PROTHENA CORP PLC | PRTA | G72800108 | $11.2M | 1.55% | 1,143,155 | SH |
| 23 | TRAVERE THERAPEUTICS INC | TVTX | 89422G107 | $9.5M | 1.32% | 167,525 | SH |
| 24 | TAYSHA GENE THERAPIES INC | TSHA | 877619106 | $9.5M | 1.31% | 1,391,382 | SH |
| 25 | ACLARIS THERAPEUTICS INC | ACRS | 00461U105 | $8.5M | 1.18% | 1,613,430 | SH |
| 26 | AGIOS PHARMACEUTICALS INC | AGIO | 00847X104 | $7.9M | 1.10% | 213,601 | SH |
| 27 | CAPRICOR THERAPEUTICS INC | CAPR | 14070B309 | $5.5M | 0.76% | 229,763 | SH |
| 28 | ALIGN TECHNOLOGY INC | ALGN | 016255101 | $5.3M | 0.73% | 31,389 | SH |
| 29 | ORUKA THERAPEUTICS INC - Restricted | ORKA | 687604108 | $3.2M | 0.44% | 33,546 | SH |
| 30 | XENON PHARMACEUTICALS INC | XENE | 98420N105 | $3.1M | 0.43% | 51,345 | SH |
| 31 | NEUROCRINE BIOSCIENCES INC | NBIX | 64125C109 | $3.1M | 0.42% | 18,117 | SH |
| 32 | EDWARDS LIFESCIENCES CORP | EW | 28176E108 | $3.0M | 0.42% | 33,640 | SH |
| 33 | STOKE THERAPEUTICS INC | STOK | 86150R107 | $2.8M | 0.38% | 84,631 | SH |
| 34 | CYTOKINETICS INC | CYTK | 23282W605 | $2.7M | 0.38% | 32,195 | SH |
| 35 | PYXIS ONCOLOGY INC | PYXS | 747324101 | $2.6M | 0.36% | 864,277 | SH |
| 36 | EHEALTH INC | EHTH | 28238P109 | $2.2M | 0.31% | 1,482,797 | SH |
| 37 | CRISPR THERAPEUTICS AG | CRSP | H17182108 | $2.2M | 0.30% | 39,605 | SH |
| 38 | SAGIMET BIOSCIENCES INC-A | SGMT | 786700104 | $1.9M | 0.27% | 250,000 | SH |
| 39 | NUVATION BIO INC | NUVB | 67080N101 | $1.9M | 0.26% | 326,609 | SH |
| 40 | BIONTECH SE-ADR | BNTX | 09075V102 | $1.8M | 0.25% | 19,614 | SH |
| 41 | COMPASS PATHWAYS PLC ADR | CMPS | 20451W101 | $1.6M | 0.23% | 115,616 | SH |
| 42 | HUMANA INC | HUM | 444859102 | $1.6M | 0.22% | 3,985 | SH |
| 43 | NEWAMSTERDAM PHARMA CO NV | NAMS | N62509109 | $1.5M | 0.21% | 44,359 | SH |
| 44 | VERASTEM INC | VSTM | 92337C203 | $1.2M | 0.16% | 309,685 | SH |
| 45 | MADRIGAL PHARMACEUTICALS INC | MDGL | 558868105 | $959.5K | 0.13% | 1,787 | SH |
| 46 | UROGEN PHARMA LTD | URGN | M96088105 | $901.6K | 0.12% | 24,500 | SH |
| 47 | BICYCLE THERAPEUTICS PLC-ADR | BCYC | 088786108 | $856.0K | 0.12% | 201,890 | SH |
| 48 | XERIS BIOPHARMA HOLDINGS INC | XERS | 98422E103 | $826.9K | 0.11% | 104,410 | SH |
| 49 | ABEONA THERAPEUTICS INC | ABEO | 00289Y206 | $672.8K | 0.09% | 108,865 | SH |
| 50 | INSPIRE MEDICAL SYSTEMS INC | INSP | 457730109 | $391.3K | 0.05% | 8,772 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-06-30 | 2026-08-18 | $723.7M | 52 | 0002073679-26-000101 |
| 2026-06-30 | 2026-08-17 | $723.7M | 52 | 0002073679-26-000096 |
| 2026-06-30 | 2026-08-19 | $723.7M | 52 | 0002073679-26-000102 |
| 2026-03-31 | 2026-05-15 | $653.9M | 51 | 0001306923-26-000004 |
| 2025-12-31 | 2026-02-17 | $718.4M | 49 | 0001306923-26-000002 |
| 2025-09-30 | 2025-11-14 | $540.4M | 44 | 0001306923-25-000019 |