| $385M | ||
| $350M | ||
| $215M | ||
| $82M | ||
| $76M | ||
| $62M |
Buys | $0 | 0 | 0 |
Sells | $50,839,807 | 3 | 100 |
| EcoR1 Capital, LLC | 10 percent owner | 0 | $0 | 3 | $50.84M | $-50.84M |
Prothena Corporation plc, a late-stage clinical company, focuses on discovery and development of novel therapies for life-threatening diseases in the United States. The company is involved in developing Birtamimab, an investigational humanized antibody that is in Phase III clinical trial for the treatment of AL amyloidosis; Prasinezumab, a humanized monoclonal antibody, which is in Phase IIb clinical trial for the treatment of Parkinson's disease; PRX004 that completed Phase I clinical trial for the treatment of Transthyretin amyloidosis; and PRX005, which is in Phase I clinical trial for the treatment of Alzheimer's disease. Its discovery and preclinical programs include PRX012 for the treatment of Alzheimer's disease; and dual Aß-Tau vaccine for the treatment and prevention of Alzheimer's disease. Prothena Corporation plc has a license, development, and commercialization agreement with F. Hoffmann-La Roche Ltd. and Hoffmann-La Roche Inc. to develop and commercialize antibodies that target alpha-synuclein; and a collaboration agreement with Bristol-Myers Squibb to develop antibodies. The company was founded in 2012 and is based in Dublin, Ireland.
Over the last 12 months, insiders at Prothena Corporation plc have bought $0 and sold $50.84M worth of Prothena Corporation plc stock.
On average, over the past 5 years, insiders at Prothena Corporation plc have bought $27.05M and sold $37.99M worth of stock each year.
There was no buying activity among insiders over the last 12 months.
The last purchase of 100,000 shares for transaction amount of $1.28M was made by SCULLY WILLIAM P (10 percent owner) on 2025‑01‑14.
| 2025-05-06 | Sale | EcoR1 Capital, LLC | 10 percent owner | 1.98M 3.8331% | $7.64 | $15.16M | +19.83% | |
| 2025-05-05 | Sale | EcoR1 Capital, LLC | 10 percent owner | 977,693 1.8234% | $8.11 | $7.93M | +8.79% | |
| 2025-05-02 | Sale | EcoR1 Capital, LLC | 10 percent owner | 3.32M 6.0641% | $8.36 | $27.74M | +3.30% | |
| 2025-01-14 | SCULLY WILLIAM P | 10 percent owner | 100,000 0.1889% | $12.79 | $1.28M | -24.31% | ||
| 2024-12-31 | SCULLY WILLIAM P | 10 percent owner | 32,000 0.0565% | $13.01 | $416,393 | -29.78% | ||
| 2024-12-20 | SCULLY WILLIAM P | 10 percent owner | 2,000 0.0038% | $15.91 | $31,813 | -35.15% | ||
| 2024-12-18 | SCULLY WILLIAM P | 10 percent owner | 73,436 0.1611% | $13.93 | $1.02M | -17.15% | ||
| 2024-01-24 | Sale | Walker Karin L | Chief Accounting Officer | 5,000 0.0096% | $34.00 | $170,000 | -36.62% | |
| 2023-12-20 | Sale | Walker Karin L | Chief Accounting Officer | 5,000 0.0094% | $37.19 | $185,952 | -41.90% | |
| 2023-11-30 | Sale | Walker Karin L | Chief Accounting Officer | 5,000 0.0097% | $34.00 | $170,000 | -32.54% | |
| 2023-10-25 | Sale | Walker Karin L | Chief Accounting Officer | 5,000 0.0097% | $41.04 | $205,191 | -41.33% | |
| 2023-10-11 | Sale | Smith Brandon S. | Chief Operating Officer | 4,000 0.0074% | $46.75 | $186,985 | -49.30% | |
| 2023-10-04 | Sale | Karp Carol D. | Chief Regulatory Officer | 5,000 0.0093% | $46.62 | $233,084 | -46.37% | |
| 2023-09-27 | Sale | Malecek Michael J | Chief Legal Officer | 5,000 0.0093% | $47.38 | $236,885 | -47.78% | |
| 2023-09-19 | Sale | Walker Karin L | Chief Accounting Officer | 5,000 0.0093% | $52.36 | $261,807 | -51.52% | |
| 2023-09-13 | Sale | Smith Brandon S. | Chief Operating Officer | 4,000 0.0075% | $55.49 | $221,963 | -51.85% | |
| 2023-09-13 | Sale | Garren Hideki | Chief Medical Officer | 2,000 0.0037% | $55.48 | $110,952 | -51.85% | |
| 2023-09-06 | Sale | Karp Carol D. | Chief Regulatory Officer | 5,000 0.0093% | $54.76 | $273,804 | -51.62% | |
| 2023-08-30 | Sale | Malecek Michael J | Chief Legal Officer | 5,000 0.0095% | $55.01 | $275,066 | -49.87% | |
| 2023-08-18 | Sale | Walker Karin L | Chief Accounting Officer | 5,000 0.0096% | $57.18 | $285,923 | -50.22% |
| EcoR1 Capital, LLC | 10 percent owner | 5304596 9.8538% | $50.18M | 9 | 4 | +87.11% |
| SCULLY WILLIAM P | 10 percent owner | 735993 1.3672% | $6.96M | 4 | 0 | <0.0001% |
| Kinney Gene G. | President and CEO | 12793 0.0238% | $121,021.78 | 1 | 13 | +13.42% |
| Schenk Dale B. | President and CEO | 3333 0.0062% | $31,530.18 | 1 | 2 | +5.51% |
| Nguyen Tran | Chief Strategy Officer and CFO | 3200 0.0059% | $30,272.00 | 2 | 10 | +10.25% |
| Selkoe Dennis J. | director | 2845 0.0053% | $26,913.70 | 0 | 17 | |
| Nickerson Tara | Chief Business Officer | 2000 0.0037% | $18,920.00 | 1 | 7 | +5.51% |
| COLLIER RICHARD T | director | 1219 0.0023% | $11,531.74 | 0 | 6 | |
| Ekman Lars | director | 243 0.0005% | $2,298.78 | 0 | 6 | |
| HOMAN ARTHUR W | Chief Legal Officer | 0 0% | $0 | 1 | 9 | +21.36% |
| HENNEY CHRISTOPHER S | director | 0 0% | $0 | 0 | 10 | |
| Cooke Shane | director | 0 0% | $0 | 0 | 7 | |
| Walker Karin L | Chief Accounting Officer | 0 0% | $0 | 0 | 28 | |
| Koller Martin | Chief Medical Officer | 0 0% | $0 | 0 | 3 | |
| PERRIGO Co plc | 10 percent owner | 0 0% | $0 | 0 | 1 | |
| Karp Carol D. | Chief Regulatory Officer | 0 0% | $0 | 0 | 8 | |
| Zago Wagner M. | Chief Scientific Officer | 0 0% | $0 | 0 | 7 | |
| Malecek Michael J | Chief Legal Officer | 0 0% | $0 | 0 | 13 | |
| Smith Brandon S. | Chief Operating Officer | 0 0% | $0 | 0 | 5 | |
| Garren Hideki | Chief Medical Officer | 0 0% | $0 | 0 | 11 |
$3,611,891 | 113 | 13.40% | $496.37M | |
$63,049,419 | 31 | 2.87% | $501.27M | |
$79,019,806 | 27 | 7.24% | $446.78M | |
$4,306,464 | 21 | 37.34% | $462.2M | |
$2,516,932 | 19 | -15.78% | $569.54M | |
Prothena Corporation plc (PRTA) | $112,238,340 | 19 | 39.16% | $509.26M |
$46,858,891 | 18 | -11.58% | $574.76M | |
$104,137,421 | 15 | 21.28% | $502.15M | |
$7,254,955 | 14 | 20.70% | $535.83M | |
$57,263,116 | 11 | -8.37% | $519.13M | |
$15,099,668 | 11 | 3.51% | $467.54M | |
$140,543,039 | 10 | 0.77% | $562.63M | |
$49,165,200 | 7 | 12.92% | $581.31M | |
$166,385 | 7 | -23.62% | $580.45M | |
$144,224 | 4 | 21.31% | $494.86M | |
$58,352 | 4 | -43.78% | $528.19M | |
$10,104,842 | 3 | 5.45% | $493.39M | |
$2,857,000 | 2 | -5.23% | $520.28M | |
$300,016 | 1 | -50.33% | $468.43M |
| Increased Positions | 89 | +42.18% | 9M | +21.58% |
| Decreased Positions | 87 | -41.23% | 5M | -11.11% |
| New Positions | 26 | New | 792,512 | New |
| Sold Out Positions | 28 | Sold Out | 1M | Sold Out |
| Total Postitions | 213 | +0.95% | 47M | +10.46% |
| Fmr Llc | $72,691.00 | 14.63% | 7.9M | 0 | 0% | 2025-09-30 |
| Blackrock, Inc. | $33,105.00 | 6.66% | 3.6M | -340,981 | -8.66% | 2025-09-30 |
| Vanguard Group Inc | $18,859.00 | 3.8% | 2.05M | -126,378 | -5.81% | 2025-09-30 |
| Armistice Capital, Llc | $16,781.00 | 3.38% | 1.82M | -412,000 | -18.43% | 2025-09-30 |
| Rubric Capital Management Lp | $14,171.00 | 2.85% | 1.54M | +2M | New | 2025-09-30 |
| Adar1 Capital Management, Llc | $13,516.00 | 2.72% | 1.47M | -2M | -56.47% | 2025-09-30 |
| Palo Alto Investors Lp | $12,181.00 | 2.45% | 1.32M | +49,275 | +3.87% | 2025-09-30 |
| D. E. Shaw & Co., Inc. | $12,102.00 | 2.44% | 1.32M | +923,923 | +236% | 2025-09-30 |
| Acadian Asset Management Llc | $11,401.00 | 2.3% | 1.24M | +221,065 | +21.71% | 2025-09-30 |
| Geode Capital Management, Llc | $9,379.00 | 1.89% | 1.02M | +86,037 | +9.22% | 2025-09-30 |