PRTA · Insider Trading
Prothena Corporation plc Ordinary Shares
Every open-market purchase and sale reported by PRTA officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-11-10 | William P Scully | 10%+ Owner | MIXED | −776,444 | +$1.19M |
| 2026-10-29 | William P Scully | 10%+ Owner | G | +566,444 | — |
| 2026-10-26 | William P Scully | 10%+ Owner | Buy | +150,000 | +$1.22M |
| 2026-10-15 | William P Scully | 10%+ Owner | Buy | +110,000 | +$920.05K |
| 2026-10-09 | William P Scully | 10%+ Owner | Buy | +215,000 | +$1.82M |
| 2026-10-06 | William P Scully | 10%+ Owner | Buy | +100,000 | +$857.24K |
| 2026-09-30 | William P Scully | 10%+ Owner | Buy | +162,000 | +$1.41M |
| 2026-09-29 | William P Scully | 10%+ Owner | Buy | +103,500 | +$889.87K |
| 2026-09-21 | William P Scully | 10%+ Owner | Buy | +100,000 | +$843.46K |
| 2026-09-03 | William P Scully | 10%+ Owner | Buy | +27,000 | +$255.74K |
| 2026-08-21 | William P Scully | 10%+ Owner | Buy | +50,000 | +$439.43K |
| 2026-08-18 | William P Scully | 10%+ Owner | G | −291,553 | — |
| 2026-08-11 | William P Scully | 10%+ Owner | G | +251,553 | — |
| 2026-08-10 | William P Scully | 10%+ Owner | Buy | +37,500 | +$323.22K |
| 2026-07-30 | Anne Evans Kingston | Chief Strategy Officer | MIXED | −11,160 | −$94.86K |
| 2026-07-30 | Karin L Walker | Chief Accounting Officer | MIXED | — | −$128.40K |
| 2026-07-30 | Tran Nguyen | Chief Strategy Officer and CFO | MIXED | — | −$487.92K |
| 2026-07-30 | Brandon S. Smith | Chief Operating Officer | MIXED | — | −$667.68K |
| 2026-07-30 | Michael John Isaacs | General Counsel & Company Sec. | MIXED | −13,080 | −$111.24K |
| 2026-07-30 | Chad J. Swanson | Chief Development Officer | MIXED | +6,733 | −$378.93K |
| 2026-07-30 | Wagner M. Zago | Chief Scientific Officer | MIXED | — | −$436.56K |
| 2026-07-30 | Gene G. Kinney | President and CEO | MIXED | — | −$719.04K |
| 2026-06-18 | William P Scully | 10%+ Owner | Buy | +20,000 | +$157.99K |
| 2026-06-16 | William P Scully | 10%+ Owner | G | −325,000 | — |
| 2026-06-12 | William P Scully | 10%+ Owner | Buy | +125,000 | +$1.02M |
| 2026-06-05 | William P Scully | 10%+ Owner | Buy | +50,000 | +$465.29K |
| 2026-06-03 | William P Scully | 10%+ Owner | Buy | +50,000 | +$471.30K |
| 2026-05-26 | William P Scully | 10%+ Owner | Buy | +100,000 | +$981.30K |
| 2026-05-15 | Shane Cooke | Director | A | +27,000 deriv. | — |
| 2026-05-15 | Lars Ekman | Director | A | +27,000 deriv. | — |
| 2026-05-15 | Dennis J. Selkoe | Director | A | +27,000 deriv. | — |
| 2026-05-15 | Richard T Collier | Director | A | +27,000 deriv. | — |
| 2026-05-15 | William H. Dunn Jr. | Director | A | +27,000 deriv. | — |
| 2026-05-15 | Daniel G Welch | Director | A | +27,000 deriv. | — |
| 2026-04-10 | Anne Evans Kingston | Chief Strategy Officer | A | +100,000 deriv. | — |
| 2026-03-05 | Tran Nguyen | Chief Strategy Officer and CFO | A | +230,000 deriv. | — |
| 2026-03-05 | Wagner M. Zago | Chief Scientific Officer | A | +190,000 deriv. | — |
| 2026-03-05 | Gene G. Kinney | President and CEO | A | +520,000 deriv. | — |
| 2026-03-05 | Karin L Walker | Chief Accounting Officer | A | +150,000 deriv. | — |
| 2026-03-05 | Chad J. Swanson | Chief Development Officer | A | +190,000 deriv. | — |
| 2026-03-05 | Brandon S. Smith | Chief Operating Officer | A | +190,000 deriv. | — |
| 2026-03-05 | Michael J Malecek | Chief Legal Officer | A | +190,000 deriv. | — |
| 2025-07-30 | Michael J Malecek | Chief Legal Officer | A | +80,000 | — |
| 2025-07-30 | Karin L Walker | Chief Accounting Officer | A | +25,000 | — |
| 2025-07-30 | Brandon S. Smith | Chief Operating Officer | A | +130,000 | — |
| 2025-07-30 | Wagner M. Zago | Chief Scientific Officer | A | +85,000 | — |
| 2025-07-30 | Tran Nguyen | Chief Strategy Officer and CFO | A | +95,000 | — |
| 2025-07-30 | Gene G. Kinney | President and CEO | A | +140,000 | — |
| 2025-07-30 | Chad J. Swanson | Chief Development Officer | A | +85,000 | — |
| 2025-05-16 | Shane Cooke | Director | A | +20,183 deriv. | — |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| EcoR1 Capital, LLC | 10%+ Owner | 8,266,342 | $70.76M |
| William P Scully | 10%+ Owner | 1,940,444 | $16.61M |
| Tran Nguyen | Chief Strategy Officer and CFO | 97,205 | $832.07K |
| Wagner M. Zago | Chief Scientific Officer | 85,000 | $727.60K |
| Michael J Malecek | Chief Legal Officer | 80,000 | $684.80K |
| Gene G. Kinney | President and CEO | 68,793 | $588.87K |
| Anne Evans Kingston | Chief Strategy Officer | 55,782 | $477.49K |
| Brandon S. Smith | Chief Operating Officer | 52,000 | $445.12K |
| Chad J. Swanson | Chief Development Officer | 40,733 | $348.67K |
| Michael John Isaacs | General Counsel & Company Sec. | 35,745 | $305.98K |
| Karin L Walker | Chief Accounting Officer | 25,000 | $214.00K |
| Dennis J. Selkoe | Director | 9,208 | $78.82K |
| Richard T Collier | Director | 6,219 | $53.23K |
| Lars Ekman | Director | 3,148 | $26.95K |
Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.
Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.
Full filing history and per-insider positions are on the PRTA quote page; the site-wide leaderboard is on the insider transactions hub.
Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.