Palo Alto Investors’s Prothena Corp PRTA Stock Holding History
Bought
Maintained
Sold
| Quarter | Market Value | Status | Shares |
Change in Stake | Trade Value | Portfolio Weight | Portfolio Position | |
|---|---|---|---|---|---|---|---|---|
|
2026
Q2 | $11.2M | Sell |
1,143,155
-65,413
| -5% | -$646K | 1.55% | 22 |
|
|
2026
Q1 | $11.7M | Sell |
1,208,568
-111,942
| -8% | -$1.03M | 1.8% | 17 |
|
|
2025
Q4 | $12.6M | Sell |
1,320,510
-3,518
| -0.3% | -$35.8K | 1.76% | 16 |
|
|
2025
Q3 | $12.9M | Buy |
1,324,028
+49,275
| +4% | +$379K | 2.39% | 15 |
|
|
2025
Q2 | $7.74M | Sell |
1,274,753
-384,981
| -23% | -$2.89M | 1.65% | 13 |
|
|
2025
Q1 | $20.5M | Sell |
1,659,734
-78,230
| -5% | -$1.11M | 3.91% | 9 |
|
|
2024
Q4 | $24.1M | Hold |
1,737,964
| – | – | 3.73% | 10 |
|
|
2024
Q3 | $29.1M | Buy |
1,737,964
+71,586
| +4% | +$1.54M | 3.78% | 9 |
|
|
2024
Q2 | $34.4M | Buy |
1,666,378
+2,930
| +0.2% | +$63.4K | 3.99% | 9 |
|
|
2024
Q1 | $41.2M | Buy |
1,663,448
+3,391
| +0.2% | +$101K | 4.65% | 8 |
|
|
2023
Q4 | $60.3M | Buy |
1,660,057
+2,599
| +0.2% | +$100K | 5.44% | 7 |
|
|
2023
Q3 | $80M | Hold |
1,657,458
| – | – | 7.57% | 6 |
|
|
2023
Q2 | $113M | Sell |
1,657,458
-6,319
| -0.4% | -$408K | 9.14% | 6 |
|
|
2023
Q1 | $80.6M | Buy |
1,663,777
+5,200
| +0.3% | +$275K | 6.68% | 8 |
|
|
2022
Q4 | $99.9M | Buy |
1,658,577
+8,800
| +0.5% | +$515K | 8.52% | 6 |
|
|
2022
Q3 | $100M | Sell |
1,649,777
-31,700
| -2% | -$1M | 7.91% | 7 |
|
|
2022
Q2 | $45.7M | Hold |
1,681,477
| – | – | 3.98% | 9 |
|
|
2022
Q1 | $61.5M | Sell |
1,681,477
-3,805
| -0.2% | -$137K | 4.75% | 9 |
|
|
2021
Q4 | $83.3M | Hold |
1,685,282
| – | – | 5.32% | 8 |
|
|
2021
Q3 | $120M | Sell |
1,685,282
-46,200
| -3% | -$2.87M | 7.25% | 6 |
|
|
2021
Q2 | $89M | Sell |
1,731,482
-11,023
| -0.6% | -$344K | 4.91% | 9 |
|
|
2021
Q1 | $43.8M | Buy |
1,742,505
+50,700
| +3% | +$954K | 2.49% | 15 |
|
|
2020
Q4 | $20.3M | Buy |
1,691,805
+363,071
| +27% | +$4.29M | 1.07% | 18 |
|
|
2020
Q3 | $13.3M | Buy |
1,328,734
+557,669
| +72% | +$6.71M | 0.73% | 21 |
|
|
2020
Q2 | $8.06M | Sell |
771,065
-4,231
| -0.5% | -$47K | 0.48% | 22 |
|
|
2020
Q1 | $8.3M | Sell |
775,296
-217,453
| -22% | -$2.63M | 0.69% | 21 |
|
|
2019
Q4 | $15.7M | Sell |
992,749
-11,700
| -1% | -$125K | 0.87% | 20 |
|
|
2019
Q3 | $7.88M | Sell |
1,004,449
-104,061
| -9% | -$924K | 0.52% | 22 |
|
|
2019
Q2 | $11.7M | Hold |
1,108,510
| – | – | 0.57% | 24 |
|
|
2019
Q1 | $13.4M | Hold |
1,108,510
| – | – | 0.56% | 24 |
|
|
2018
Q4 | $11.4M | Buy |
1,108,510
+5,185
| +0.5% | +$61.6K | 0.61% | 24 |
|
|
2018
Q3 | $14.4M | Hold |
1,103,325
| – | – | 0.58% | 24 |
|
|
2018
Q2 | $16.1M | Buy |
1,103,325
+1,987
| +0.2% | +$39.3K | 0.64% | 24 |
|
|
2018
Q1 | $40.4M | Buy |
1,101,338
+5,683
| +0.5% | +$207K | 1.73% | 18 |
|
|
2017
Q4 | $41.1M | Hold |
1,095,655
| – | – | 1.77% | 18 |
|
|
2017
Q3 | $71M | Buy |
1,095,655
+21,700
| +2% | +$1.33M | 2.99% | 10 |
|
|
2017
Q2 | $58.1M | Buy |
1,073,955
+18,100
| +2% | +$964K | 2.71% | 13 |
|
|
2017
Q1 | $58.9M | Buy |
1,055,855
+62,000
| +6% | +$3.26M | 2.78% | 12 |
|
|
2016
Q4 | $48.9M | Buy |
993,855
+59,400
| +6% | +$3.28M | 2.79% | 12 |
|
|
2016
Q3 | $56M | Buy |
934,455
+145,837
| +18% | +$7.82M | 3.26% | 11 |
|
|
2016
Q2 | $27.6M | Buy |
788,618
+93,100
| +13% | +$4.05M | 2.08% | 15 |
|
|
2016
Q1 | $28.6M | Hold |
695,518
| – | – | 2.22% | 12 |
|
|
2015
Q4 | $47.4M | Sell |
695,518
-400
| -0.1% | -$24.1K | 2.64% | 10 |
|
|
2015
Q3 | $31.6M | Hold |
695,918
| – | – | 1.52% | 13 |
|
|
2015
Q2 | $36.7M | Hold |
695,918
| – | – | 1.63% | 14 |
|
|
2015
Q1 | $26.5M | Buy |
695,918
+4,700
| +0.7% | +$121K | 1.31% | 19 |
|
|
2014
Q4 | $14.3M | Buy |
691,218
+17,400
| +3% | +$363K | 0.84% | 26 |
|
|
2014
Q3 | $14.9M | Buy |
673,818
+139,800
| +26% | +$2.96M | 1.12% | 24 |
|
|
2014
Q2 | $12M | Buy |
534,018
+1,100
| +0.2% | +$27.5K | 0.9% | 29 |
|
|
2014
Q1 | $20.4M | Sell |
532,918
-4,500
| -0.8% | -$145K | 1.69% | 17 |
|
|
2013
Q4 | $14.3M | Buy |
537,418
+448,918
| +507% | +$11.3M | 1.33% | 20 |
|
|
2013
Q3 | $1.79M | Hold |
88,500
| – | – | 0.19% | 29 |
|
|
2013
Q2 | $1.14M | Buy |
+88,500
| New | +$823K | 0.13% | 30 |
|
Other funds holding PRTA
RCMNY
ACM
Palo Alto Investors's PRTA Position: Q2 2026 in Review
Palo Alto Investors reduced its Prothena Corp (PRTA) stake by 5.4% in Q2 2026, selling an estimated $646K and leaving 1,143,155 shares worth $11.2M. The position accounts for 1.55% of the portfolio, ranked #22.
Palo Alto Investors first reported a position in PRTA in Q2 2013 and has held it in 53 quarters since. The position peaked at $120M in Q3 2021. 188 funds tracked by Wall St. Rank hold PRTA as of Q2 2026.
- Palo Alto Investors held 1,143,155 shares of Prothena Corp worth $11.2M as of Q2 2026.
- Palo Alto Investors sold 65,413 Prothena Corp shares in Q2 2026, an estimated $646K.
- Prothena Corp made up 1.55% of Palo Alto Investors's portfolio in Q2 2026, its #22 holding.
- Palo Alto Investors first reported a position in Prothena Corp in Q2 2013 and has held it in 53 quarters since.
- Palo Alto Investors's Prothena Corp position peaked at $120M in Q3 2021.
- 188 funds tracked by Wall St. Rank held Prothena Corp as of Q2 2026.
Based on Palo Alto Investors's 13F filing for Q2 2026, filed 17 Aug 2026.