Follow The Filings

Palo Alto Investors LP Palo Alto Investors

Palo Alto, CA 23 processed 13Fs on this site, 2021 Q3 to 2026 Q2

  • $724M
  • 52 holdings
  • 2026 Q2
  • +10.7% QoQ
  • Top 5 37.7%

Portfolio

2026 Q2, filed 8/19/2026, top 12 of 52 holdings

Top 5 37.7%, top 10 61.3%

  1. PTC, PTC Therapeutics 10.4%
  2. ACAD, Acadia Pharmaceuticals 10.0%
  3. INSM, Insmed 6.1%
  4. MIRM, Mirum Pharmaceuticals 5.6%
  5. ANAB, Anaptysbio 5.6%
  6. BMRN, Biomarin Pharmaceutical 5.4%
  7. DYN, Dyne Therapeutics 5.1%
  8. UTHR, United Therapeutics 4.7%
  9. IRON, Disc Medicine 4.2%
  10. BIIB, Biogen 4.2%
  11. IOVA, Iovance Biotherapeutics 3.0%
  12. RARE 2.8%
  13. Other 32.9%

AUM over time

2026 Q2 $724M +10.7% QoQ
2021 Q3: $1.7B 2021 Q3: $1.7B
Q3 2021
2021 Q4: $1.6B, −5.6% QoQ 2021 Q4: $1.6B, −5.6% QoQ
Q4
2022 Q1: $1.3B, −17.4% QoQ 2022 Q1: $1.3B, −17.4% QoQ
Q1 2022
2022 Q2: $1.1B, −11.3% QoQ 2022 Q2: $1.1B, −11.3% QoQ
Q2
2022 Q3: $1.3B, +10.3% QoQ 2022 Q3: $1.3B, +10.3% QoQ
Q3
2022 Q4: $1.2B, −7.3% QoQ 2022 Q4: $1.2B, −7.3% QoQ
Q4
2023 Q1: $1.2B, +2.9% QoQ 2023 Q1: $1.2B, +2.9% QoQ
Q1 2023
2023 Q2: $1.2B, +2.6% QoQ 2023 Q2: $1.2B, +2.6% QoQ
Q2
2023 Q3: $1.1B, −14.6% QoQ 2023 Q3: $1.1B, −14.6% QoQ
Q3
2023 Q4: $1.1B, +4.7% QoQ 2023 Q4: $1.1B, +4.7% QoQ
Q4
2024 Q1: $887M, −19.9% QoQ 2024 Q1: $887M, −19.9% QoQ
Q1 2024
2024 Q2: $863M, −2.7% QoQ 2024 Q2: $863M, −2.7% QoQ
Q2
2024 Q3: $770M, −10.8% QoQ 2024 Q3: $770M, −10.8% QoQ
Q3
2024 Q4: $645M, −16.2% QoQ 2024 Q4: $645M, −16.2% QoQ
Q4
2025 Q1: $525M, −18.6% QoQ 2025 Q1: $525M, −18.6% QoQ
Q1 2025
2025 Q2: $470M, −10.5% QoQ 2025 Q2: $470M, −10.5% QoQ
Q2
2025 Q3: $540M, +14.9% QoQ 2025 Q3: $540M, +14.9% QoQ
Q3
2025 Q4: $718M, +33.0% QoQ 2025 Q4: $718M, +33.0% QoQ
Q4
2026 Q1: $654M, −8.9% QoQ 2026 Q1: $654M, −8.9% QoQ
Q1 2026
2026 Q2: $724M, +10.7% QoQ 2026 Q2: $724M, +10.7% QoQ
Q2

Book

2025 Q3 2025 Q2, filed 14 Nov, long equity only

Download CSV Download Excel All activity
INSM, Insmed 13.11%, was 18.52% Reduce −43.2% 491,805 $144.01 $71M −373,308 −$16M
PTC, PTC Therapeutics 9.80%, was 4.22% Add +112.2% 862,613 $61.37 $53M +456,144 +$33M
ACAD, Acadia Pharmaceuticals 9.74%, was 11.76% Reduce −3.8% 2,466,684 $21.34 $53M −96,525 −$2.6M
FOLD, Amicus 7.83% Reduce −4.3% 5,367,798 $7.88 $42M −242,715 +$10M
BMRN, Biomarin Pharmaceutical 7.56%, was 9.83% Reduce −10.3% 754,007 $54.16 $41M −86,463 −$5.4M
BIIB, Biogen 4.81%, was 5.50% Reduce −9.8% 185,661 $140.08 $26M −20,098 +$166K
UTHR, United Therapeutics 4.51%, was 5.84% Reduce −39.1% 58,186 $419.21 $24M −37,296 −$3M
ANAB, Anaptysbio 3.82%, was 3.84% Reduce −17.1% 673,520 $30.62 $21M −139,301 +$2.6M
IOVA, Iovance Biotherapeutics 3.06%, was 1.25% Add +122.1% 7,618,132 $2.17 $17M +4,188,803 +$11M
NVCR, Novocure 3.00% Add +30.5% 1,256,159 $12.92 $16M +293,763 −$901K
DYN, Dyne Therapeutics 2.96%, was 0.54% Add +376.5% 1,262,674 $12.65 $16M +997,698 +$13M
IRON, Disc Medicine 2.74%, was 1.64% Add +54.0% 224,300 $66.08 $15M +78,609 +$7.1M
ALNY, Alnylam Pharmaceuticals 2.73%, was 5.24% Reduce −57.2% 32,320 $456.00 $15M −43,215 −$9.9M
Gossamer Bio 2.66% Reduce −4.8% 5,464,349 $2.63 $14M −274,664 +$7.3M
PRTA, Prothena 2.39%, was 1.65% Add +3.9% 1,324,028 $9.76 $13M +49,275 +$5.2M
RARE 2.06%, was 0.38% Add +658.0% 369,531 $30.08 $11M +320,781 +$9.3M
AGIO, Agios Pharmaceuticals 1.97% Reduce −1.2% 265,497 $40.14 $11M −3,286 +$1.7M
SNDX, Syndax Pharmaceuticals 1.86%, was 0.89% Add +47.4% 654,930 $15.38 $10M +210,563 +$5.9M
EHTH, Ehealth 1.23%, was 1.46% Reduce −2.1% 1,544,619 $4.31 $6.7M −33,231 −$206K
DNLI, Denali Therapeutics 1.10%, was 0.71% Add +70.1% 408,006 $14.52 $5.9M +168,197 +$2.6M
ALGN, Align Technology 1.06% Add +21.1% 45,735 $125.22 $5.7M +7,963 −$1.4M
ALKS, Alkermes 1.02%, was 1.35% Reduce −16.8% 183,938 $30.00 $5.5M −37,083 −$805K
RNA, Avidity Biosciences 0.89% Reduce −7.6% 109,831 $43.57 $4.8M −9,055 +$1.4M
MIRM, Mirum Pharmaceuticals 0.88% Hold 64,700 $73.31 $4.7M — —
CDNA, Caredx 0.85% New 316,204 $14.54 $4.6M +316,204 +$4.6M
TSHA, Taysha Gene Therapies 0.75% Hold 1,246,033 $3.27 $4.1M — —
NUVB, Nuvation Bio 0.70%, was 0.32% Add +32.1% 1,020,547 $3.70 $3.8M +247,895 +$2.3M
ACRS, Aclaris Therapeutics 0.55%, was 0.42% Add +12.7% 1,566,840 $1.90 $3M +176,812 +$1M
CRSP, Crispr Therapeutics 0.49% Reduce −7.6% 41,226 $64.81 $2.7M −3,399 +$501K
TVTX, Travere Therapeutics 0.49% Hold 110,719 $23.90 $2.6M — —
EW, Edwards Lifesciences 0.48%, was 0.66% Reduce −14.8% 33,640 $77.77 $2.6M −5,833 −$471K
NBIX, Neurocrine Biosciences 0.47%, was 0.36% Add +35.9% 18,117 $140.38 $2.5M +4,783 +$867K
STOK, Stoke Therapeutics 0.46% Reduce −16.2% 105,427 $23.50 $2.5M −20,434 +$1M
PYXS, Pyxis Oncology 0.43% Hold 1,037,421 $2.22 $2.3M — —
BNTX, Biontech Se-Adr 0.36%, was 0.57% Reduce −22.2% 19,614 $98.62 $1.9M −5,592 −$749K
BCYC 0.32%, was 0.37% Reduce −11.2% 221,071 $7.74 $1.7M −27,863 −$19K
ALDX, Aldeyra Therapeutics 0.22% Hold 225,465 $5.22 $1.2M — —
HUM, Humana 0.19% Hold 3,985 $260.17 $1M — —
ORKA, Oruka Therapeutics 0.15% New 59,985 $13.19 $791K +59,985 +$791K
ABEO, Abeona Therapeutics 0.11% Hold 108,865 $5.28 $575K — —
URGN, Urogen 0.09% Hold 24,500 $19.95 $489K — —
PRQR, Proqr Therapeutics 0.07% New 188,807 $2.13 $402K +188,807 +$402K
Akari Therapeutics Plc-Adr 0.03% Hold 146,024 $1.01 $147K — —
Generation Bio 0.02% Reduce −90.0% 15,047 $6.12 $92K −135,428 +$44K

Exits / last held

Gone since 2025 Q2, shown at their last reported size.

Stock % of portfolio Recent activity Shares Reported price* Value Share change $ change
Staar Surgical 2.83% Exit 0 $16.78 $13M −791,879 −$13M
KPTI, Karyopharm Therapeutics 0.17% Exit 0 $4.31 $810K −187,911 −$810K
Vyne Therapeutics Inc. Pipe 0.16% Exit 0 $1.65 $735K −445,434 −$735K
ALMS, Alumis 0.09% Exit 0 $3.00 $430K −143,437 −$430K

Weight bar: held both quarters added sold at this quarter’s reported price

* Reported price is value ÷ shares from the 13F as of period end, not a live market quote. Weight % is each long-equity position ÷ full 13F AUM, so rows may not sum to 100% when the filing includes options or other non-equity (excluded from this table). Share change and $ change are vs 2025 Q2. Click a column header to sort, or New, Hold, Add or Reduce to bring those moves to the top. Exit opens the last-held block below.

Filings history

20 periods, with AUM normalized

Newest 13Fs
Period Holds AUM QoQ Form Filed Filing ID
2026 Q2 52 $724M +10.7% RESTATEMENT 8/19/2026 000207367926000102
2026 Q2 52 $724M — RESTATEMENT 8/18/2026 000207367926000101
2026 Q2 52 $724M — 13F-HR 8/17/2026 000207367926000096
2026 Q1 51 $654M −8.9% 13F-HR 5/15/2026 000130692326000004
2025 Q4 49 $718M +33.0% 13F-HR 2/17/2026 000130692326000002
2025 Q3 44 $540M +14.9% 13F-HR 11/14/2025 000130692325000019
2025 Q2 45 $470M −10.5% 13F-HR 8/14/2025 000130692325000016
2025 Q1 44 $525M −18.6% 13F-HR 5/15/2025 000130692325000014
2024 Q4 43 $645M −16.2% 13F-HR 2/14/2025 000130692325000010
2024 Q3 45 $770M −10.8% 13F-HR 11/14/2024 000130692324000012
2024 Q2 39 $863M −2.7% 13F-HR 8/14/2024 000130692324000010
2024 Q1 38 $887M −19.9% 13F-HR 5/15/2024 000130692324000008
2023 Q4 34 $1.1B — RESTATEMENT 2/15/2024 000130692324000007
2023 Q4 34 $1.1B +4.7% 13F-HR 2/14/2024 000130692324000002
2023 Q3 29 $1.1B −14.6% 13F-HR 11/14/2023 000130692323000014
2023 Q2 30 $1.2B +2.6% 13F-HR 8/14/2023 000130692323000012
2023 Q1 30 $1.2B +2.9% 13F-HR 5/15/2023 000130692323000011
2022 Q4 29 $1.2B −7.3% 13F-HR 2/14/2023 000130692323000009
2022 Q3 32 $1.3B +10.3% 13F-HR 11/14/2022 000130692322000016
2022 Q2 33 $1.1B −11.3% 13F-HR 8/15/2022 000130692322000015
2022 Q1 35 $1.3B −17.4% 13F-HR 5/16/2022 000130692322000014
2021 Q4 37 $1.6B −5.6% 13F-HR 2/14/2022 000130692322000004
2021 Q3 42 $1.7B — 13F-HR 11/15/2021 000130692321000026

About

Palo Alto Investors LP

23 processed 13Fs on this site, 2021 Q3 to 2026 Q2

Entity
Palo Alto Investors LP
Notable person
Palo Alto Investors
Location
Palo Alto, CA
All SEC filings
View on sec.gov