Palo Alto Investors LP holds a focused book of 52 stocks worth $723.7M as of Q2 2026 (disclosed Aug 19, 2026, a ~50-day 13F lag). This quarter they opened First Tracks Biotherapeutics and trimmed PTC Therapeutics Inc. Their largest long position is PTC Therapeutics Inc at 10% of the equity book.
Top-heavy: focused book
Share of the disclosed book in its largest positions. A higher top-5 share means a more concentrated, higher-conviction portfolio.
100% mapped to company sectors
Direct operating-company sectors from our SIC-based security master. ETF/fund and unclassified holdings stay visible separately; this is not ETF look-through exposure.
Estimated $ traded · quarter-end prices, no cost basis
Other tracked managers holding the same core names as Palo Alto Investors LP
| Manager / fund | Shared names | Their $ in those |
|---|---|---|
| BlackRock, Inc. | 54 / 52 | $27.7B |
| GEODE CAPITAL MANAGEMENT, LLC | 54 / 52 | $8.4B |
| JPMORGAN CHASE & CO | 54 / 52 | $8.1B |
| MORGAN STANLEY | 54 / 52 | $3.4B |
| UBS Group AG | 54 / 52 | $2.3B |
| BNP PARIBAS FINANCIAL MARKETS | 54 / 52 | $965.9M |
| ROYAL BANK OF CANADA | 54 / 52 | $568.5M |
| WELLS FARGO & COMPANY/MN | 54 / 52 | $487.7M |
Ranked by how many of Palo Alto Investors LP's top 52 disclosed names each fund also holds: a cross-fund conviction signal from the latest 13F of every tracked manager.
Bars show each stock's share of the portfolio. Click a row for its position history.
| # | Security | Value | Shares | % Port | Last move | History |
|---|---|---|---|---|---|---|
| 1 | PTC Therapeutics Inc COM | $75.0M | 918.8K | 10.4% | ▼−0.3% Reduced · −3K sh | |
| 2 | Acadia Pharmaceuticals Inc COM | $72.5M | 2.86M | 10.0% | ▼−0.3% Reduced · −9K sh | |
| 3 | Insmed Inc COM PAR $.01 | $44.1M | 414.0K | 6.1% | ▼−0.3% Reduced · −1K sh | |
| 4 | Mirum Pharmaceuticals Inc COM | $40.8M | 348.8K | 5.6% | ▲+7.3% Added · +24K sh | |
| 5 | Anaptysbio Inc COM | $40.7M | 603.5K | 5.6% | ▼−5.4% Reduced · −35K sh | |
| 6 | Biomarin Pharmaceutical Inc COM | $39.1M | 682.8K | 5.4% | ▼−0.3% Reduced · −2K sh | |
| 7 | Dyne Therapeutics Inc COM | $36.6M | 1.65M | 5.1% | ▼−0.3% Reduced · −5K sh | |
| 8 | United Therapeutics Corp COM | $33.9M | 62.6K | 4.7% | ▼−0.3% Reduced · −222 sh | |
| 9 | Disc Medicine Inc COM | $30.5M | 416.6K | 4.2% | ▲+3.7% Added · +15K sh | |
| 10 | Biogen Inc COM | $30.3M | 140.3K | 4.2% | ▼−0.3% Reduced · −440 sh | |
| 11 | Iovance Biotherapeutics Inc COM | $22.0M | 5.30M | 3.0% | ▼−17% Reduced · −1.1M sh | |
| 12 | Ultragenyx Pharmaceutical In COM | $19.9M | 596.5K | 2.8% | —Held | |
| 13 | Novocure Ltd ORD SHS | $19.4M | 1.28M | 2.7% | —Held | |
| 14 | Syndax Pharmaceuticals Inc COM | $18.9M | 865.0K | 2.6% | —Held | |
| 15 | Annexon Inc COM | $16.8M | 2.95M | 2.3% | —Held | |
| 16 | Bicara Therapeutics Inc COM | $16.3M | 550.4K | 2.3% | —Held | |
| 17 | Caredx Inc COM | $15.2M | 531.9K | 2.1% | —Held | |
| 18 | Celldex Therapeutics Inc COM NEW | $14.9M | 399.9K | 2.1% | ▲+35% Added · +103K sh | |
| 19 | Compass Therapeutics Inc COM | $12.8M | 5.83M | 1.8% | ▲+285% Added · +4.3M sh | |
| 20 | Alkermes PLC SHS | $12.7M | 242.6K | 1.8% | —Held | |
| 21 | First Tracks Biotherapeutics ORD SHS | $12.1M | 603.5K | 1.7% | ▲New New position | |
| 22 | Prothena Corp PLC SHS | $11.2M | 1.14M | 1.5% | ▼−5.4% Reduced · −65K sh | |
| 23 | Travere Therapeutics Inc COM | $9.5M | 167.5K | 1.3% | ▼−27% Reduced · −63K sh | |
| 24 | Taysha Gene Therapies Inc COM SHS | $9.5M | 1.39M | 1.3% | —Held | |
| 25 | Aclaris Therapeutics Inc COM | $8.5M | 1.61M | 1.2% | —Held | |
| 26 | Agios Pharmaceuticals Inc COM | $7.9M | 213.6K | 1.1% | —Held | |
| 27 | Capricor Therapeutics Inc COM NEW | $5.5M | 229.8K | 0.8% | —Held | |
| 28 | Align Technology Inc COM | $5.3M | 31.4K | 0.7% | ▼−24% Reduced · −10K sh | |
| 29 | Oruka Therapeutics Inc - Restricted COM | $3.2M | 33.5K | 0.4% | ▼−44% Reduced · −26K sh | |
| 30 | Xenon Pharmaceuticals Inc COM | $3.1M | 51.3K | 0.4% | —Held | |
| 31 | Neurocrine Biosciences Inc COM | $3.1M | 18.1K | 0.4% | —Held | |
| 32 | Edwards Lifesciences Corp COM | $3.0M | 33.6K | 0.4% | —Held | |
| 33 | Stoke Therapeutics Inc COM | $2.8M | 84.6K | 0.4% | —Held | |
| 34 | Cytokinetics Inc COM NEW | $2.7M | 32.2K | 0.4% | —Held | |
| 35 | Pyxis Oncology Inc COMMON STOCK | $2.6M | 864.3K | 0.4% | ▼−14% Reduced · −146K sh | |
| 36 | Ehealth Inc COM | $2.2M | 1.48M | 0.3% | —Held | |
| 37 | Crispr Therapeutics AG NAMEN AKT | $2.2M | 39.6K | 0.3% | —Held | |
| 38 | Sagimet Biosciences Inc-A COM SER A | $1.9M | 250.0K | 0.3% | ▲New New position | |
| 39 | Nuvation Bio Inc COM CL A | $1.9M | 326.6K | 0.3% | ▼−36% Reduced · −182K sh | |
| 40 | Biontech SE-ADR SPONSORED ADS | $1.8M | 19.6K | 0.3% | —Held | |
| 41 | Compass Pathways PLC ADR SPONSORED ADS | $1.6M | 115.6K | 0.2% | —Held | |
| 42 | Humana Inc COM | $1.6M | 4.0K | 0.2% | —Held | |
| 43 | Newamsterdam Pharma Co NV ORDINARY SHARES | $1.5M | 44.4K | 0.2% | ▲New New position | |
| 44 | Verastem Inc COM NEW | $1.2M | 309.7K | 0.2% | ▲+26% Added · +64K sh | |
| 45 | Madrigal Pharmaceuticals Inc COM | $960K | 1.8K | 0.1% | —Held | |
| 46 | Urogen Pharma Ltd COM | $902K | 24.5K | 0.1% | —Held | |
| 47 | Bicycle Therapeutics PLC-ADR SPONSORED ADS | $856K | 201.9K | 0.1% | —Held | |
| 48 | Xeris Biopharma Holdings Inc COM | $827K | 104.4K | 0.1% | —Held | |
| 49 | Abeona Therapeutics Inc COM NEW | $673K | 108.9K | 0.1% | —Held | |
| 50 | Inspire Medical Systems Inc COM | $391K | 8.8K | 0.1% | —Held |
The public view is the crawlable proof. The same sourced dataset is available through REST and MCP for agents, research scripts, and back-office tools.
This fund page is the Follow view. The Build view lets your agent pull holdings, quarter changes, overlap, and source filings through API or MCP.
curl -H "Authorization: Bearer YOUR_API_KEY" \ "https://arkolith.com/api/v1/funds/1306923/holdings"
Use Arkolith to show Palo Alto Investors LP's latest holdings, largest changes, and filing provenance.
As-of date vs the date the SEC received each filing
| Quarter | As of | Filed | Positions | Value | Form |
|---|---|---|---|---|---|
| Q2 2026 | Jun 30, 2026 | Aug 19, 2026 | 52 | $723.7M | 13F-HR/A |
| Q1 2026 | Mar 31, 2026 | May 15, 2026 | 51 | $653.9M | 13F-HR |
| Q4 2025 | Dec 31, 2025 | Feb 17, 2026 | 49 | $718.4M | 13F-HR |
| Q3 2025 | Sep 30, 2025 | Nov 14, 2025 | 44 | $540.4M | 13F-HR |
| Q2 2025 | Jun 30, 2025 | Aug 14, 2025 | 45 | $470.0M | 13F-HR |
Holdings from SEC EDGAR 13F-HR filings, updated quarterly, filed up to 45 days after quarter-end. Public domain. The book and weighting are long equity only; disclosed put/call options are listed separately and excluded from those totals. Price-derived performance is withheld until the price-source policy and freshness gate are green.