Prothena Corporation plc (PRTA)
Who owns Prothena Corporation plc (PRTA)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 70.1% of the shares are freely tradable; institutional investors hold 90.7%.
Ownership Structure
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| FMR Inc | 14.42 | 7,551,218 | +0.0 | 03/31/2026 |
| Rubric Capital Management LP | 9.55 | 5,000,000 | +36.0 | 03/31/2026 |
| BlackRock Inc | 8.87 | 4,644,160 | +13.1 | 03/31/2026 |
| Vanguard Group Inc | 4.09 | 2,140,909 | +4.4 | 12/31/2025 |
| State Street Corp | 3.70 | 1,938,498 | -14.5 | 03/31/2026 |
| D. E. Shaw & Co LP | 3.37 | 1,763,347 | +4.9 | 03/31/2026 |
| ADAR1 Capital Management LLC | 3.02 | 1,581,443 | +8.5 | 03/31/2026 |
| Acadian Asset Management LLC | 2.96 | 1,547,593 | +1,457.7 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Fidelity Growth Compy Commingled Pl S | 6.55 | 3,428,791 | +0.0 | 04/30/2026 |
| Fidelity Growth Company Fund | 4.38 | 2,294,229 | +0.0 | 04/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| 29. Jul 2026 | Kingston Anne Evans | Chief Strategy Officer | Sell | 7,662 | 8.47 | 64,919 |
| 29. Jul 2026 | Isaacs Michael John | General Counsel & Company Sec. | Sell | 8,386 | 8.47 | 71,055 |
| 28. Jul 2026 | Zago Wagner M. | Chief Scientific Officer | Other | 51,000 | 8.56 | 436,560 |
| 28. Jul 2026 | Zago Wagner M. | Chief Scientific Officer | Other | 51,000 | – | – |
| 28. Jul 2026 | Walker Karin L | Chief Accounting Officer | Other | 15,000 | 8.56 | 128,400 |
| 28. Jul 2026 | Walker Karin L | Chief Accounting Officer | Other | 15,000 | – | – |
| 28. Jul 2026 | Swanson Chad J. | Chief Development Officer | Other | 3,467 | 8.56 | 29,678 |
| 28. Jul 2026 | Swanson Chad J. | Chief Development Officer | Other | 40,800 | 8.56 | 349,248 |
| 28. Jul 2026 | Swanson Chad J. | Chief Development Officer | Other | 51,000 | – | – |
| 28. Jul 2026 | Smith Brandon S. | Chief Operating Officer | Other | 78,000 | 8.56 | 667,680 |
| 28. Jul 2026 | Smith Brandon S. | Chief Operating Officer | Other | 78,000 | – | – |
| 28. Jul 2026 | Nguyen Tran | Chief Strategy Officer and CFO | Other | 57,000 | 8.56 | 487,920 |
| 28. Jul 2026 | Nguyen Tran | Chief Strategy Officer and CFO | Other | 57,000 | – | – |
| 28. Jul 2026 | Kinney Gene G. | President and CEO | Other | 84,000 | 8.56 | 719,040 |
| 28. Jul 2026 | Kinney Gene G. | President and CEO | Other | 84,000 | – | – |
| 28. Jul 2026 | Kingston Anne Evans | Chief Strategy Officer | Other | 3,498 | 8.56 | 29,943 |
| 28. Jul 2026 | Isaacs Michael John | General Counsel & Company Sec. | Other | 4,694 | 8.56 | 40,181 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character.
View all insider transactions →Data as of: July 31, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.