PRTA · Prothena Corporation plc Ordinary Shares
View on chartInsiders & Stakes
| EcoR1 Capital, LLC 10% Owner | ▼ Sell | Open Market | 5,304,596 Shares held | 5/6/2025 | View profile |
| William P. Scully 10% Owner | ▲ Buy | Open Market | 529,000 Shares held | 10/8/2026 | View profile |
| Michael J. Malecek See Remarks | ▲ Buy | Grant | 80,000 Shares held | 7/28/2025 | View profile |
| Gene G. Kinney President and CEO | ▼ Sell | Other | 68,793 Shares held | 7/28/2026 | View profile |
| Anne Evans Kingston Chief Strategy Officer | ▼ Sell | Open Market | 55,782 Shares held | 7/29/2026 | View profile |
| Brandon S. Smith Chief Operating Officer | ▼ Sell | Other | 52,000 Shares held | 7/28/2026 | View profile |
| Chad J. Swanson Chief Development Officer | ▼ Sell | Tax Withholding | 40,733 Shares held | 7/28/2026 | View profile |
| Tran Nguyen Chief Strategy Officer and CFO | ▼ Sell | Other | 40,205 Shares held | 7/28/2026 | View profile |
| Michael John Isaacs General Counsel & Company Sec. | ▼ Sell | Open Market | 35,745 Shares held | 7/29/2026 | View profile |
| Wagner M. Zago Chief Scientific Officer | ▼ Sell | Other | 34,000 Shares held | 7/28/2026 | View profile |
| Karin L. Walker Chief Accounting Officer | ▼ Sell | Other | 10,000 Shares held | 7/28/2026 | View profile |
| Selkoe Dennis J. | ▼ Sell | Open Market | 2,845 Shares held | 7/3/2023 | View profile |
| COLLIER RICHARD T Director | ▼ Sell | Open Market | 1,219 Shares held | 1/5/2023 | View profile |
| Ekman Lars Director | ▼ Sell | Open Market | 243 Shares held | 1/3/2023 | View profile |
| Garren Hideki Chief Medical Officer | ▼ Sell | Open Market | 0 Shares held | 9/13/2023 | View profile |
| Karp Carol D. Chief Regulatory Officer | ▼ Sell | Open Market | 0 Shares held | 10/4/2023 | View profile |
| Cooke Shane Director | ▼ Sell | Open Market | 0 Shares held | 1/10/2023 | View profile |
Transaction History
| William P. Scully | ▲ Buy | Open Market | 90,000 | $771K | 10/8/2026 |
| William P. Scully | ▲ Buy | Open Market | 125,000 | $1.1M | 10/7/2026 |
| William P. Scully | ▲ Buy | Open Market | 100,000 | $857K | 10/2/2026 |
| William P. Scully | ▲ Buy | Open Market | 162,000 | $1.4M | 9/29/2026 |
| William P. Scully | ▲ Buy | Open Market | 103,500 | $890K | 9/28/2026 |
| William P. Scully | ▲ Buy | Open Market | 100,000 | $843K | 9/18/2026 |
| William P. Scully | ▲ Buy | Open Market | 27,000 | $256K | 9/2/2026 |
| William P. Scully | ▲ Buy | Open Market | 50,000 | $439K | 8/20/2026 |
| William P. Scully | ▼ Sell | Gift | 627,553 | $0 | 8/18/2026 |
| William P. Scully | ▼ Sell | Gift | 336,000 | $0 | 8/17/2026 |
| William P. Scully | ▼ Sell | Gift | 251,553 | $0 | 8/10/2026 |
| William P. Scully | ▲ Buy | Open Market | 34,000 | $293K | 8/7/2026 |
| William P. Scully | ▲ Buy | Open Market | 3,500 | $30K | 8/7/2026 |
| Anne Evans Kingston | ▼ Sell | Open Market | 7,662 | $65K | 7/29/2026 |
| Michael John Isaacs | ▼ Sell | Open Market | 8,386 | $71K | 7/29/2026 |
| Wagner M. Zago | ▲ Buy | Option Exercise | 51,000 | — | 7/28/2026 |
| Wagner M. Zago | ▼ Sell | Other | 51,000 | $437K | 7/28/2026 |
| Karin L. Walker | ▲ Buy | Option Exercise | 15,000 | — | 7/28/2026 |
| Chad J. Swanson | ▼ Sell | Other | 40,800 | $349K | 7/28/2026 |
| Chad J. Swanson | ▼ Sell | Tax Withholding | 3,467 | $30K | 7/28/2026 |
| Brandon S. Smith | ▲ Buy | Option Exercise | 78,000 | — | 7/28/2026 |
| Brandon S. Smith | ▼ Sell | Other | 78,000 | $668K | 7/28/2026 |
| Tran Nguyen | ▼ Sell | Other | 57,000 | $488K | 7/28/2026 |
| Gene G. Kinney | ▲ Buy | Option Exercise | 84,000 | — | 7/28/2026 |
| Gene G. Kinney | ▼ Sell | Other | 84,000 | $719K | 7/28/2026 |
| Anne Evans Kingston | ▼ Sell | Tax Withholding | 3,498 | $30K | 7/28/2026 |
| Michael John Isaacs | ▼ Sell | Tax Withholding | 4,694 | $40K | 7/28/2026 |
| Tran Nguyen | ▲ Buy | Option Exercise | 57,000 | — | 7/28/2026 |
| Karin L. Walker | ▼ Sell | Other | 15,000 | $128K | 7/28/2026 |
| Chad J. Swanson | ▲ Buy | Option Exercise | 51,000 | — | 7/28/2026 |
| William P. Scully | ▲ Buy | Open Market | 20,000 | $158K | 6/16/2026 |
| William P. Scully | ▼ Sell | Gift | 325,000 | $0 | 6/15/2026 |
| William P. Scully | ▲ Buy | Open Market | 125,000 | $1.0M | 6/11/2026 |
| William P. Scully | ▲ Buy | Open Market | 50,000 | $465K | 6/4/2026 |
| William P. Scully | ▲ Buy | Open Market | 50,000 | $471K | 6/2/2026 |
| William P. Scully | ▲ Buy | Open Market | 100,000 | $981K | 5/22/2026 |
| Wagner M. Zago | ▲ Buy | Grant | 85,000 | $0 | 7/28/2025 |
| Karin L. Walker | ▲ Buy | Grant | 25,000 | $0 | 7/28/2025 |
| Chad J. Swanson | ▲ Buy | Grant | 85,000 | $0 | 7/28/2025 |
| Brandon S. Smith | ▲ Buy | Grant | 130,000 | $0 | 7/28/2025 |
| Tran Nguyen | ▲ Buy | Grant | 95,000 | $0 | 7/28/2025 |
| Michael J. Malecek | ▲ Buy | Grant | 80,000 | $0 | 7/28/2025 |
| Gene G. Kinney | ▲ Buy | Grant | 140,000 | $0 | 7/28/2025 |
| EcoR1 Capital, LLC | ▼ Sell | Open Market | 1,984,053 | $15.2M | 5/6/2025 |
| EcoR1 Capital, LLC | ▼ Sell | Open Market | 977,693 | $7.9M | 5/5/2025 |
| EcoR1 Capital, LLC | ▼ Sell | Open Market | 3,317,938 | $27.7M | 5/2/2025 |
| William P. Scully | ▼ Sell | Gift | 12,000 | $0 | 1/15/2025 |
| William P. Scully | ▲ Buy | Open Market | 100,000 | $1.3M | 1/14/2025 |
| William P. Scully | ▼ Sell | Gift | 1,000 | $0 | 1/3/2025 |
| William P. Scully | ▼ Sell | Gift | 13,200 | $0 | 1/2/2025 |
| William P. Scully | ▲ Buy | Open Market | 1,200 | $16K | 12/31/2024 |
| William P. Scully | ▲ Buy | Open Market | 800 | $11K | 12/31/2024 |
| William P. Scully | ▲ Buy | Open Market | 30,000 | $390K | 12/31/2024 |
| William P. Scully | ▲ Buy | Open Market | 2,000 | $32K | 12/20/2024 |
| William P. Scully | ▼ Sell | Gift | 500 | $0 | 12/20/2024 |
| William P. Scully | ▼ Sell | Gift | 40,000 | $0 | 12/20/2024 |
| William P. Scully | ▼ Sell | Gift | 681,000 | $0 | 12/19/2024 |
| William P. Scully | ▲ Buy | Open Market | 73,436 | $1.0M | 12/18/2024 |
| William P. Scully | ▼ Sell | Gift | 430,000 | $0 | 12/18/2024 |
| Karin L. Walker | ▲ Buy | Option Exercise | 5,000 | $68K | 1/24/2024 |
| Karin L. Walker | ▼ Sell | Open Market | 5,000 | $170K | 1/24/2024 |
| Karin L. Walker | ▼ Sell | Open Market | 3,322 | $124K | 12/20/2023 |
| Karin L. Walker | ▲ Buy | Option Exercise | 5,000 | $68K | 12/20/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 1,678 | $62K | 12/20/2023 |
| Karin L. Walker | ▲ Buy | Option Exercise | 5,000 | $68K | 11/30/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 5,000 | $170K | 11/30/2023 |
| Karin L. Walker | ▲ Buy | Option Exercise | 5,000 | $68K | 10/25/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 1,789 | $72K | 10/25/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 2,917 | $121K | 10/25/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 294 | $12K | 10/25/2023 |
| Brandon S. Smith | ▲ Buy | Option Exercise | 4,000 | $44K | 10/11/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 3,556 | $166K | 10/11/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 444 | $21K | 10/11/2023 |
| Karp Carol D. | ▲ Buy | Option Exercise | 5,000 | $61K | 10/4/2023 |
| Karp Carol D. | ▼ Sell | Open Market | 4,337 | $202K | 10/4/2023 |
| Karp Carol D. | ▼ Sell | Open Market | 663 | $31K | 10/4/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 4,596 | $217K | 9/27/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 404 | $20K | 9/27/2023 |
| Michael J. Malecek | ▲ Buy | Option Exercise | 5,000 | $51K | 9/27/2023 |
| Karin L. Walker | ▲ Buy | Option Exercise | 5,000 | $75K | 9/19/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 5,000 | $262K | 9/19/2023 |
| Garren Hideki | ▲ Buy | Option Exercise | 2,000 | $50K | 9/13/2023 |
| Garren Hideki | ▼ Sell | Open Market | 2,000 | $111K | 9/13/2023 |
| Brandon S. Smith | ▲ Buy | Option Exercise | 4,000 | $44K | 9/13/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 3,886 | $216K | 9/13/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 114 | $6K | 9/13/2023 |
| Karp Carol D. | ▲ Buy | Option Exercise | 5,000 | $61K | 9/6/2023 |
| Karp Carol D. | ▼ Sell | Open Market | 4,994 | $273K | 9/6/2023 |
| Karp Carol D. | ▼ Sell | Open Market | 6 | $332 | 9/6/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 2,322 | $127K | 8/30/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 2,664 | $148K | 8/30/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 14 | $787 | 8/30/2023 |
| Michael J. Malecek | ▲ Buy | Option Exercise | 5,000 | $51K | 8/30/2023 |
| Karin L. Walker | ▲ Buy | Option Exercise | 5,000 | $75K | 8/18/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 5,000 | $286K | 8/18/2023 |
| Garren Hideki | ▲ Buy | Option Exercise | 2,000 | $50K | 8/16/2023 |
| Garren Hideki | ▼ Sell | Open Market | 878 | $51K | 8/16/2023 |
| Garren Hideki | ▼ Sell | Open Market | 748 | $44K | 8/16/2023 |
| Garren Hideki | ▼ Sell | Open Market | 374 | $22K | 8/16/2023 |
| Brandon S. Smith | ▲ Buy | Option Exercise | 4,000 | $44K | 8/16/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 2,226 | $130K | 8/16/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 1,373 | $81K | 8/16/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 401 | $24K | 8/16/2023 |
| Wagner M. Zago | ▲ Buy | Option Exercise | 4,000 | $49K | 8/2/2023 |
| Wagner M. Zago | ▼ Sell | Open Market | 3,771 | $253K | 8/2/2023 |
| Wagner M. Zago | ▼ Sell | Open Market | 229 | $16K | 8/2/2023 |
| Karp Carol D. | ▲ Buy | Option Exercise | 5,000 | $61K | 8/2/2023 |
| Karp Carol D. | ▼ Sell | Open Market | 4,672 | $313K | 8/2/2023 |
| Karp Carol D. | ▼ Sell | Open Market | 328 | $22K | 8/2/2023 |
| Michael J. Malecek | ▲ Buy | Option Exercise | 5,000 | $51K | 7/26/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 2,477 | $153K | 7/26/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 1,903 | $119K | 7/26/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 620 | $39K | 7/26/2023 |
| Karin L. Walker | ▲ Buy | Option Exercise | 5,000 | $75K | 7/19/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 3,966 | $273K | 7/19/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 1,034 | $72K | 7/19/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 3,200 | $216K | 7/12/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 800 | $54K | 7/12/2023 |
| Garren Hideki | ▼ Sell | Open Market | 92 | $6K | 7/12/2023 |
| Brandon S. Smith | ▲ Buy | Option Exercise | 4,000 | $44K | 7/12/2023 |
| Garren Hideki | ▲ Buy | Option Exercise | 2,000 | $50K | 7/12/2023 |
| Garren Hideki | ▼ Sell | Open Market | 1,908 | $129K | 7/12/2023 |
| Karp Carol D. | ▲ Buy | Option Exercise | 5,000 | $61K | 7/5/2023 |
| Karp Carol D. | ▼ Sell | Open Market | 3,966 | $270K | 7/5/2023 |
| Karp Carol D. | ▼ Sell | Open Market | 1,034 | $71K | 7/5/2023 |
| Wagner M. Zago | ▲ Buy | Option Exercise | 4,000 | $49K | 7/5/2023 |
| Wagner M. Zago | ▼ Sell | Open Market | 2,991 | $203K | 7/5/2023 |
| Wagner M. Zago | ▼ Sell | Open Market | 1,009 | $69K | 7/5/2023 |
| Selkoe Dennis J. | ▼ Sell | Open Market | 5,000 | $337K | 7/3/2023 |
| Selkoe Dennis J. | ▲ Buy | Option Exercise | 5,000 | $57K | 7/3/2023 |
| Michael J. Malecek | ▲ Buy | Option Exercise | 5,000 | $51K | 6/28/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 1,240 | $86K | 6/28/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 3,050 | $213K | 6/28/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 710 | $50K | 6/28/2023 |
| Karin L. Walker | ▲ Buy | Option Exercise | 5,000 | $75K | 6/20/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 2,000 | $136K | 6/20/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 2,471 | $172K | 6/20/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 529 | $37K | 6/20/2023 |
| Garren Hideki | ▲ Buy | Option Exercise | 7,331 | $183K | 6/16/2023 |
| Garren Hideki | ▼ Sell | Open Market | 7,331 | $542K | 6/16/2023 |
| Brandon S. Smith | ▲ Buy | Option Exercise | 5,333 | $59K | 6/14/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 1,098 | $80K | 6/14/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 1,914 | $140K | 6/14/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 959 | $72K | 6/14/2023 |
| Brandon S. Smith | ▼ Sell | Open Market | 1,362 | $103K | 6/14/2023 |
| Garren Hideki | ▲ Buy | Option Exercise | 4,669 | $116K | 6/14/2023 |
| Garren Hideki | ▼ Sell | Open Market | 509 | $37K | 6/14/2023 |
| Garren Hideki | ▼ Sell | Open Market | 971 | $71K | 6/14/2023 |
| Garren Hideki | ▼ Sell | Open Market | 2,534 | $189K | 6/14/2023 |
| Garren Hideki | ▼ Sell | Open Market | 655 | $49K | 6/14/2023 |
| Karp Carol D. | ▲ Buy | Option Exercise | 5,000 | $61K | 6/7/2023 |
| Karp Carol D. | ▲ Buy | Option Exercise | 15,000 | $203K | 6/7/2023 |
| Karp Carol D. | ▼ Sell | Open Market | 3,046 | $213K | 6/7/2023 |
| Karp Carol D. | ▼ Sell | Open Market | 12,782 | $907K | 6/7/2023 |
| Karp Carol D. | ▼ Sell | Open Market | 3,811 | $274K | 6/7/2023 |
| Karp Carol D. | ▼ Sell | Open Market | 361 | $26K | 6/7/2023 |
| Wagner M. Zago | ▲ Buy | Option Exercise | 15,000 | $447K | 6/7/2023 |
| Wagner M. Zago | ▲ Buy | Option Exercise | 4,000 | $49K | 6/7/2023 |
| Wagner M. Zago | ▼ Sell | Open Market | 2,943 | $206K | 6/7/2023 |
| Wagner M. Zago | ▼ Sell | Open Market | 12,004 | $852K | 6/7/2023 |
| Wagner M. Zago | ▼ Sell | Open Market | 3,759 | $270K | 6/7/2023 |
| Wagner M. Zago | ▼ Sell | Open Market | 294 | $22K | 6/7/2023 |
| Michael J. Malecek | ▲ Buy | Option Exercise | 5,000 | $51K | 5/31/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 3,211 | $206K | 5/31/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 1,078 | $70K | 5/31/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 711 | $47K | 5/31/2023 |
| Karin L. Walker | ▲ Buy | Option Exercise | 5,000 | $75K | 5/19/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 2,823 | $208K | 5/19/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 2,177 | $162K | 5/19/2023 |
| Gene G. Kinney | ▲ Buy | Option Exercise | 45,000 | $1.3M | 5/17/2023 |
| Gene G. Kinney | ▼ Sell | Open Market | 10,202 | $742K | 5/17/2023 |
| Gene G. Kinney | ▼ Sell | Open Market | 19,864 | $1.5M | 5/17/2023 |
| Gene G. Kinney | ▼ Sell | Open Market | 14,934 | $1.1M | 5/17/2023 |
| Tran Nguyen | ▲ Buy | Option Exercise | 45,000 | $1.3M | 5/17/2023 |
| Tran Nguyen | ▲ Buy | Option Exercise | 50,000 | $1.1M | 5/17/2023 |
| Tran Nguyen | ▼ Sell | Open Market | 14,001 | $1.0M | 5/17/2023 |
| Tran Nguyen | ▼ Sell | Open Market | 34,640 | $2.5M | 5/17/2023 |
| Tran Nguyen | ▼ Sell | Open Market | 37,044 | $2.8M | 5/17/2023 |
| Tran Nguyen | ▼ Sell | Open Market | 9,215 | $695K | 5/17/2023 |
| Tran Nguyen | ▼ Sell | Open Market | 100 | $8K | 5/17/2023 |
| Selkoe Dennis J. | ▲ Buy | Option Exercise | 6,000 | $55K | 5/3/2023 |
| Selkoe Dennis J. | ▲ Buy | Option Exercise | 9,000 | $216K | 5/3/2023 |
| Selkoe Dennis J. | ▼ Sell | Open Market | 15,000 | $855K | 5/3/2023 |
| Michael J. Malecek | ▲ Buy | Option Exercise | 5,000 | $51K | 4/26/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 4,680 | $250K | 4/26/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 320 | $17K | 4/26/2023 |
| Karin L. Walker | ▲ Buy | Option Exercise | 5,000 | $75K | 4/19/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 2,917 | $154K | 4/19/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 2,083 | $111K | 4/19/2023 |
| Michael J. Malecek | ▲ Buy | Option Exercise | 5,000 | $51K | 3/29/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 2,734 | $133K | 3/29/2023 |
| Michael J. Malecek | ▼ Sell | Open Market | 2,266 | $112K | 3/29/2023 |
| Karin L. Walker | ▲ Buy | Option Exercise | 5,000 | $75K | 3/20/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 3,903 | $185K | 3/20/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 1,097 | $53K | 3/20/2023 |
| Karin L. Walker | ▲ Buy | Option Exercise | 20,000 | $301K | 3/15/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 9,431 | $454K | 3/15/2023 |
| Karin L. Walker | ▼ Sell | Open Market | 10,569 | $514K | 3/15/2023 |
| Tran Nguyen | ▲ Buy | Option Exercise | 10,000 | $67K | 3/15/2023 |
| Tran Nguyen | ▼ Sell | Open Market | 4,802 | $231K | 3/15/2023 |
AI Market Commentary
AI-generatedAll commentary →Synthesized from recent news and fundamentals/technical data -- not human analyst commentary or trader sentiment.
September 25, 2026
Prothena included in Alzheimer's Day stock watchlist
Prothena was featured in a Yahoo Finance article listing four Alzheimer's drug stocks to watch on World Alzheimer's Day. This inclusion highlights the company's relevance in the neurodegenerative disease sector. The stock is currently trading near its 52-week low, with technical indicators showing a rejection at support levels.
Prothena included in Alzheimer's Day stock watchlist. Prothena was featured in a Yahoo Finance article listing four Alzheimer's drug stocks to watch on World Alzheimer's Day. This inclusion highlights the company's relevance in the neurodegenerative disease sector. The stock is currently trading near its 52-week low, with technical indicators showing a rejection at support levels.