Palo Alto Investors LP
Long book
$653.9M
Q1 2026
Positions
51
Top-10 weight
64%
concentration
Last quarter
+17.5%
SPY +14.8%
Turnover
15%
of book per quarter
Strategy in plain words
auto-generated from filingsPalo Alto Investors LP is a concentrated fundamental stock-picker, specialised in healthcare (98% of the long book), running a $653.9M US long book across 51 positions.
The portfolio is concentrated: the top 10 names carry 64% of the portfolio. Turnover is modest: positions are typically held for years. Current anchor positions: INSMED INC, ACADIA PHARMACEUTICALS INC, PTC THERAPEUTICS INC, BIOMARIN PHARMACEUTICAL INC, UNITED THERAPEUTICS CORP.
Over the last 9 quarters its long book ran on average 3pp per quarter ahead of the S&P 500, beating the index in 4 of 9 quarters. We rate its filings highest-signal: new buys here are worth attention.
Implied long-book return vs S&P 500
methodology: positions priced quarterly, no shorts/options Fund long book S&P 500
Q1 2024
+27.7%
Q2 2024
-3.0%
Q3 2024
-7.4%
Q4 2024
-7.0%
Q1 2025
-0.5%
Q2 2025
+24.4%
Q3 2025
+19.6%
Q4 2025
-4.4%
Q1 2026
+17.5%
Sector allocation
Healthcare 96%
Other 2%
Materials 1%
Financials 0%
Long book by quarter
What does Palo Alto own?
Q1 2026 13F| Company | Sector | Shares | Value | % of book | Change |
|---|---|---|---|---|---|
| INSM INSMED INC | Healthcare | 415.3K | $67.9M | 10.4% | -15.2% |
| ACAD ACADIA PHARMACEUTICALS INC | Healthcare | 2.9M | $63.9M | 9.8% | +15.6% |
| PTCT PTC THERAPEUTICS INC | Healthcare | 921.6K | $62.8M | 9.6% | +2.0% |
| BMRN BIOMARIN PHARMACEUTICAL INC | Healthcare | 685.2K | $38.7M | 5.9% | -8.2% |
| UTHR UNITED THERAPEUTICS CORP | Healthcare | 62.8K | $37.2M | 5.7% | +7.9% |
| ANAB ANAPTYSBIO INC | Healthcare | 638.2K | $35.4M | 5.4% | -7.5% |
| MIRM MIRUM PHARMACEUTICALS INC | Healthcare | 325.2K | $30.0M | 4.6% | +107.9% |
| DYN DYNE THERAPEUTICS INC | Healthcare | 1.7M | $30.0M | 4.6% | +12.3% |
| BIIB BIOGEN INC | Healthcare | 140.7K | $25.8M | 3.9% | -23.3% |
| IRON DISC MEDICINE INC | Healthcare | 401.7K | $25.7M | 3.9% | +26.5% |
| IOVA IOVANCE BIOTHERAPEUTICS INC | Healthcare | 6.3M | $22.3M | 3.4% | -10.8% |
| SNDX SYNDAX PHARMACEUTICALS INC | Healthcare | 865.0K | $20.2M | 3.1% | +8.9% |
| ANNX ANNEXON INC | Healthcare | 2.9M | $16.3M | 2.5% | +23.7% |
| AM6 AMICUS THERAPEUTICS INC | — | 1.1M | $16.1M | 2.5% | -78.6% |
| NVCR NOVOCURE LTD | Healthcare | 1.3M | $14.0M | 2.1% | -1.4% |
| RARE ULTRAGENYX PHARMACEUTICAL IN | Healthcare | 596.5K | $12.5M | 1.9% | +29.3% |
| PRTA PROTHENA CORP PLC | Healthcare | 1.2M | $11.7M | 1.8% | -8.5% |
| BCAX BICARA THERAPEUTICS INC | Healthcare | 550.4K | $10.9M | 1.7% | +84.3% |
| CLDX CELLDEX THERAPEUTICS INC | Materials | 296.4K | $9.4M | 1.4% | New |
| CDNA CAREDX INC | Healthcare | 531.9K | $9.2M | 1.4% | +11.2% |
| ALKS ALKERMES PLC | Healthcare | 242.6K | $8.6M | 1.3% | Held |
| CMPX COMPASS THERAPEUTICS INC | Healthcare | 1.5M | $8.0M | 1.2% | -40.2% |
| AGIO AGIOS PHARMACEUTICALS INC | Healthcare | 213.6K | $7.2M | 1.1% | +0.5% |
| ALGN ALIGN TECHNOLOGY INC | Healthcare | 41.5K | $7.1M | 1.1% | Held |
| CAPR CAPRICOR THERAPEUTICS INC | Healthcare | 229.8K | $7.0M | 1.1% | +1.5% |
| TVTX TRAVERE THERAPEUTICS INC | Healthcare | 230.5K | $6.8M | 1.0% | +108.1% |
| TSHA TAYSHA GENE THERAPIES INC | Healthcare | 1.4M | $6.2M | 1.0% | +17.6% |
| ACRS ACLARIS THERAPEUTICS INC | Healthcare | 1.6M | $6.1M | 0.9% | +3.0% |
| DNLI DENALI THERAPEUTICS INC | Healthcare | 234.6K | $4.5M | 0.7% | -63.4% |
| XENE XENON PHARMACEUTICALS INC | Healthcare | 51.3K | $3.0M | 0.5% | -46.8% |
| ORKA ORUKA THERAPEUTICS INC | Healthcare | 60.0K | $2.9M | 0.4% | Held |
| STOK STOKE THERAPEUTICS INC | Healthcare | 84.6K | $2.8M | 0.4% | +17.5% |
| EW EDWARDS LIFESCIENCES CORP | Healthcare | 33.6K | $2.7M | 0.4% | Held |
| NBIX NEUROCRINE BIOSCIENCES INC | Healthcare | 18.1K | $2.4M | 0.4% | Held |
| NUVB NUVATION BIO INC | Healthcare | 508.8K | $2.2M | 0.3% | -5.4% |
| CYTK CYTOKINETICS INC | Healthcare | 32.2K | $2.1M | 0.3% | New |
| EHTH EHEALTH INC | Financials | 1.5M | $1.9M | 0.3% | -3.2% |
| CRSP CRISPR THERAPEUTICS AG | Healthcare | 39.6K | $1.9M | 0.3% | -3.9% |
| PYXS PYXIS ONCOLOGY INC | Healthcare | 1.0M | $1.5M | 0.2% | -2.6% |
| VSTM VERASTEM INC | Healthcare | 246.1K | $1.3M | 0.2% | New |
| MDGL MADRIGAL PHARMACEUTICALS INC | Healthcare | 1.8K | $935K | 0.1% | New |
| HUM HUMANA INC | Financials | 4.0K | $691K | 0.1% | Held |
| XERS XERIS BIOPHARMA HOLDINGS INC | Healthcare | 104.4K | $606K | 0.1% | New |
| ABEO ABEONA THERAPEUTICS INC | Healthcare | 108.9K | $488K | 0.1% | Held |
| INSP INSPIRE MEDICAL SYSTEMS INC | Healthcare | 8.8K | $452K | 0.1% | Held |
| URGN UROGEN PHARMA LTD | Healthcare | 24.5K | $441K | 0.1% | Held |
| PRQR PROQR THERAPEUTICS NV | Healthcare | 188.8K | $306K | 0.0% | Held |
| ALDX ALDEYRA THERAPEUTICS INC | Healthcare | 155.7K | $263K | 0.0% | -30.9% |
13F filing history
| Period | Form | Filed | Entries | Reported value | Flags | Source |
|---|---|---|---|---|---|---|
| Q1 2026 | 13F-HR | May 15, 2026 | 51 | $653.9M | canonical | SEC ↗ |
| Q4 2025 | 13F-HR | Feb 17, 2026 | 49 | $718.4M | canonical | SEC ↗ |
| Q3 2025 | 13F-HR | Nov 14, 2025 | 44 | $540.4M | canonical | SEC ↗ |
| Q2 2025 | 13F-HR | Aug 14, 2025 | 45 | $470.0M | canonical | SEC ↗ |
| Q1 2025 | 13F-HR | May 15, 2025 | 44 | $525.1M | canonical | SEC ↗ |
| Q4 2024 | 13F-HR | Feb 14, 2025 | 43 | $645.4M | canonical | SEC ↗ |
| Q3 2024 | 13F-HR | Nov 14, 2024 | 45 | $769.9M | canonical | SEC ↗ |
| Q2 2024 | 13F-HR | Aug 14, 2024 | 39 | $863.0M | canonical | SEC ↗ |
| Q1 2024 | 13F-HR | May 15, 2024 | 38 | $886.7M | canonical | SEC ↗ |