Palo Alto Investors LP reported 51 positions worth $682.88M for the quarter ended Jun 30, 2026, up 7.1% on the prior quarter. It opened 4 new positions, added to 4, trimmed 14 and exited 3. Its largest holding is Ptc Therapeutics, Inc. at 11% of the portfolio.
Reported 13F market value at each quarter end. A change mixes trading with price moves in the positions held.
Dollar value of shares bought and sold each quarter, at that quarter’s price. It counts trading only, not price changes.
How many positions were opened, added to, trimmed or closed each quarter.
Share of reported value in each sector at every quarter end.
| Holding | Change | Change % | Trade Value | Weight |
|---|---|---|---|---|
| ACHC Acadia Healthcare Company, Inc. | +2.86M | – | $72.46M | 10.61% |
| TRAX First Tracks Biotherapeutics, Inc. | +603.5K | – | $12.14M | 1.78% |
| CMPX Compass Therapeutics, Inc. | +4.32M | +285.1% | $9.45M | 1.87% |
| CLDX Celldex Therapeutics, Inc. | +103.4K | +34.9% | $3.85M | 2.18% |
| SGMT Sagimet Biosciences Inc. | +250.0K | – | $1.93M | 0.283% |
| NAMS NewAmsterdam Pharma Co N.V. | +44.4K | – | $1.50M | 0.22% |
| IRON Disc Medicine, Inc. | +14.9K | +3.7% | $1.09M | 4.46% |
| VSTM Verastem, Inc. | +63.6K | +25.8% | $242.92K | 0.173% |
| Holding | Change | Change % | Trade Value | Weight |
|---|---|---|---|---|
| ACAD Acadia Pharmaceuticals Inc | -2.87M | -100.0% | $63.95M | Exited |
| MIRM Mirum Pharmaceuticals, Inc. | -325.2K | -100.0% | $30.04M | Exited |
| DNLI Denali Therapeutics Inc. | -234.6K | -100.0% | $4.50M | Exited |
| IOVA Iovance Biotherapeutics, Inc. | -1.05M | -16.6% | $4.38M | 3.23% |
| TVTX Travere Therapeutics, Inc. | -62.9K | -27.3% | $3.57M | 1.39% |
| ORKA Oruka Therapeutics, Inc. | -26.4K | -44.1% | $2.52M | 0.468% |
| ANAB Anaptysbio, Inc | -34.7K | -5.4% | $2.34M | 5.97% |
| ALGN Align Technology Inc | -10.1K | -24.4% | $1.71M | 0.775% |
| NUVB Nuvation Bio Inc. | -182.2K | -35.8% | $1.04M | 0.272% |
| PRTA Prothena Corp Public Ltd Co | -65.4K | -5.4% | $640.39K | 1.64% |
| # | Activity | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1 | PTCT Ptc Therapeutics, Inc. | Healthcare | 918.8K | $74.95M | 10.98% | -2,761 | -0.3% | Reduced | 1.1% |
| 2 | ACHC Acadia Healthcare Company, Inc. | Healthcare | 2.86M | $72.46M | 10.61% | +2.86M | – | New | 3.15% |
| 3 | INSM INSMED Inc | Healthcare | 414.0K | $44.14M | 6.46% | -1,289 | -0.3% | Reduced | 0.19% |
| 4 | ANAB Anaptysbio, Inc | Healthcare | 603.5K | $40.74M | 5.97% | -34.7K | -5.4% | Reduced | 2.08% |
| 5 | BMRN Biomarin Pharmaceutical Inc | Healthcare | 682.8K | $39.07M | 5.72% | -2,405 | -0.4% | Reduced | 0.35% |
| 6 | DYN Dyne Therapeutics, Inc. | Healthcare | 1.65M | $36.59M | 5.36% | -5,451 | -0.3% | Reduced | 0.99% |
| 7 | UTHR UNITED THERAPEUTICS Corp | Healthcare | 62.6K | $33.91M | 4.97% | -222 | -0.4% | Reduced | 0.15% |
| 8 | IRON Disc Medicine, Inc. | Healthcare | 416.6K | $30.47M | 4.46% | +14.9K | +3.7% | Added | 1.08% |
| 9 | BIIB Biogen Inc. | Healthcare | 140.3K | $30.31M | 4.44% | -440 | -0.3% | Reduced | 0.09% |
| 10 | IOVA Iovance Biotherapeutics, Inc. | Healthcare | 5.30M | $22.03M | 3.23% | -1.05M | -16.6% | Reduced | 1.17% |
| 11 | RARE Ultragenyx Pharmaceutical Inc. | Healthcare | 596.5K | $19.92M | 2.92% | 0 | 0.0% | Unchanged | 0.59% |
| 12 | NVCR NovoCure Ltd | Healthcare | 1.28M | $19.40M | 2.84% | 0 | 0.0% | Unchanged | 1.1% |
| 13 | SNDX Syndax Pharmaceuticals Inc | Healthcare | 865.0K | $18.91M | 2.77% | 0 | 0.0% | Unchanged | 0.97% |
| 14 | ANNX Annexon, Inc. | Healthcare | 2.95M | $16.83M | 2.47% | 0 | 0.0% | Unchanged | 1.47% |
| 15 | BCAX Bicara Therapeutics Inc. | Healthcare | 550.4K | $16.34M | 2.39% | 0 | 0.0% | Unchanged | 0.81% |
Tip. Select a row to see that position’s full history at Palo Alto Investors.
As of its Q2 2026 13F filing, Palo Alto Investors LP’s five largest positions were Ptc Therapeutics, Inc. (PTCT) at 11.0%, Acadia Healthcare Company, Inc. (ACHC) at 10.6%, INSMED Inc (INSM) at 6.5%, Anaptysbio, Inc (ANAB) at 6.0%, Biomarin Pharmaceutical Inc (BMRN) at 5.7% of the reported portfolio.
Palo Alto Investors LP reported a 13F portfolio worth $682.88M across 51 positions for Q2 2026. That is up 7.1% from the previous quarter.
Its largest purchases by value were Acadia Healthcare Company, Inc. ($72.46M), First Tracks Biotherapeutics, Inc. ($12.14M), Compass Therapeutics, Inc. ($9.45M). It opened 4 new positions.
Its largest sales by value were Acadia Pharmaceuticals Inc ($63.95M), Mirum Pharmaceuticals, Inc. ($30.04M), Denali Therapeutics Inc. ($4.50M). It exited 3 positions entirely.
From the Form 13F-HR reports Palo Alto Investors LP files with the SEC each quarter, within 45 days of quarter end. A 13F lists long positions in US-listed equities and options; it excludes short positions, cash, bonds and most non-US holdings.
13F data reflects long positions in US-listed equities and options as reported to the SEC up to 45 days after quarter end. It excludes short positions, cash, bonds and most non-US securities, so it is not a complete picture of a manager’s assets.