Palo Alto Investors
Palo Alto Investors reported 52 stocks worth $724M in its 13F filing for Q2 2026, filed Aug 19, 2026. Its largest holdings are PTCT (10.4%), ACAD (10.0%) and INSM (6.1%). Compared with Q1 2026, the fund opened new positions in TRAX, SGMT and NAMS, added to MIRM, IRON and CLDX, trimmed PTCT, ACAD and INSM and sold out of DNLI.
Holdings
| # | Stock | Value | Weight | Shares | Change | Shares, 8 qtrs | Held |
|---|---|---|---|---|---|---|---|
| 1 |  PTCT Ptc Therapeutics Inc | $75M | 10.4% | 919K | −2,761 (−0%) | 8 of 8 | |
| 2 |  ACAD Acadia Pharmaceuticals Inc | $72.5M | 10.0% | 2.9M | −8,599 (−0%) | 8 of 8 | |
| 3 |  INSM Insmed Inc | $44.1M | 6.1% | 414K | −1,289 (−0%) | 8 of 8 | |
| 4 |  MIRM Mirum Pharmaceuticals Inc | $40.8M | 5.6% | 349K | +24K (+7%) | 8 of 8 | |
| 5 |  ANAB Anaptysbio Inc | $40.7M | 5.6% | 603K | −35K (−5%) | 8 of 8 | |
| 6 |  BMRN Biomarin Pharmaceutical Inc | $39.1M | 5.4% | 683K | −2,405 (−0%) | 8 of 8 | |
| 7 |  DYN Dyne Therapeutics Inc | $36.6M | 5.1% | 1.6M | −5,451 (−0%) | 6 of 8 | |
| 8 |  UTHR United Therapeutics Corp Del | $33.9M | 4.7% | 63K | −222 (−0%) | 8 of 8 | |
| 9 |  IRON Disc Medicine Inc | $30.5M | 4.2% | 417K | +15K (+4%) | 5 of 8 | |
| 10 |  BIIB Biogen Inc | $30.3M | 4.2% | 140K | −440 (−0%) | 8 of 8 |
Positions at Jun 30, 2026, as reported. Change is against the fund's Q1 2026 filing; weight is the share of the fund's reported stocks.
Sold out
held in Q1 2026, gone in Q2 2026| Stock | Value last quarter | Shares sold |
|---|---|---|
AMICUS THERAPEUTICS INC | $16.1M | 1.1M |
 DNLI Denali Therapeutics Inc | $4.5M | 235K |
Reported value
last 8 quartersThe value of the US stocks the fund reported, at quarter end prices. It moves with the market as well as with buying and selling.
Filings for Q2 2026
straight from the SEC| Filed | Form | Quarter | |
|---|---|---|---|
| Aug 19, 2026 | 13F-HR/A Amendment | Q2 2026 | SEC filing ↗ |
| Aug 18, 2026 | 13F-HR/A Amendment | Q2 2026 | SEC filing ↗ |
| Aug 17, 2026 | 13F-HR | Q2 2026 | SEC filing ↗ |
Includes an amendment, which can add positions the fund kept confidential at first, or replace the original report.
Other superinvestors
All hedge fund holdings →Palo Alto Investors 13F FAQ
What does Palo Alto Investors own?
Palo Alto Investors reported 52 stocks worth $724M in its 13F filing for Q2 2026, filed Aug 19, 2026. Its largest holdings are PTCT (10.4%), ACAD (10.0%) and INSM (6.1%). The table above lists every position in the filing (the top 10 without an account).
What did Palo Alto Investors buy and sell in Q2 2026?
Compared with Q1 2026: 3 new positions, 5 added to, 15 trimmed and 2 sold out. New positions include TRAX, SGMT and NAMS. It sold all of DNLI.
When will Palo Alto Investors file its next 13F?
Holdings as of Sep 30, 2026 are due by Nov 16, 2026. The filing appears on this page within minutes of reaching the SEC.
How much is Palo Alto Investors's portfolio worth?
The Q2 2026 filing reports $724M in US stocks. That leaves out cash, bonds, short positions and most foreign holdings, so the fund's total assets are usually larger.
For informational and educational purposes only. Not investment advice, and not a recommendation to buy or sell any security. Holdings come from the fund's SEC Form 13F filings as reported and show positions at the end of the quarter, up to 45 days before the filing. The fund may have changed its positions since. A 13F leaves out short positions, cash, bonds and most foreign holdings. See all hedge fund holdings.