Prothena Corporation plc (PRTA) Insider Trading
Over the last 3 months, PRTA insiders made 5 open-market buys and 0 sales, a net purchase of $3.1M (SEC Form 4). Over the last 6 months, 134 institutions increased and 110 reduced their position (13F).
Insider Activity
Sentiment
100/100
Buys (3m)
5
Sells (3m)
0
Net (3m)
$3.1M
Insiders buying
Insider trades by month Buys Sells
Nov
Dec
Jan
May
May
Jun
Context3-month price +0.7%Institutions mixed (13F)
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| Jun 18, 2026 | SCULLY WILLIAM P10 percent owner | Buy | 20,000 | $7.90 |
| Jun 12, 2026 | SCULLY WILLIAM P10 percent owner | Buy | 125,000 | $8.17 |
| Jun 5, 2026 | SCULLY WILLIAM P10 percent owner | Buy | 50,000 | $9.31 |
| Jun 3, 2026 | SCULLY WILLIAM P10 percent owner | Buy | 50,000 | $9.43 |
| May 26, 2026 | SCULLY WILLIAM P10 percent owner | Buy | 100,000 | $9.81 |
| May 15, 2026 | Dunn William H. Jr.director | Grant | 27,000 | $9.76 |
| May 15, 2026 | Ekman Larsdirector | Grant | 27,000 | $9.76 |
| May 15, 2026 | COLLIER RICHARD Tdirector | Grant | 27,000 | $9.76 |
| May 15, 2026 | Selkoe Dennis J.director | Grant | 27,000 | $9.76 |
| May 15, 2026 | WELCH DANIEL Gdirector | Grant | 27,000 | $9.76 |
| May 15, 2026 | Cooke Shanedirector | Grant | 27,000 | $9.76 |
| Apr 10, 2026 | Kingston Anne Evansofficer: Chief Strategy Officer | Grant | 100,000 | $10.50 |
| Mar 5, 2026 | Smith Brandon S.officer: Chief Operating Officer | Grant | 190,000 | $9.36 |
| Mar 5, 2026 | Nguyen Tranofficer: Chief Strategy Officer and CFO | Grant | 230,000 | $9.36 |
| Mar 5, 2026 | Walker Karin Lofficer: Chief Accounting Officer | Grant | 150,000 | $9.36 |
| Mar 5, 2026 | Zago Wagner M.officer: Chief Scientific Officer | Grant | 190,000 | $9.36 |
| Mar 5, 2026 | Malecek Michael Jofficer: Chief Legal Officer | Grant | 190,000 | $9.36 |
| Mar 5, 2026 | Kinney Gene G.director, officer: President and CEO | Grant | 520,000 | $9.36 |
| Mar 5, 2026 | Swanson Chad J.officer: Chief Development Officer | Grant | 190,000 | $9.36 |
| Jul 30, 2025 | Kinney Gene G.director, officer: President and CEO | Grant | 140,000 | — |
| Jul 30, 2025 | Swanson Chad J.officer: Chief Development Officer | Grant | 85,000 | — |
| Jul 30, 2025 | Malecek Michael Jofficer: Chief Legal Officer | Grant | 80,000 | — |
| Jul 30, 2025 | Nguyen Tranofficer: Chief Strategy Officer and CFO | Grant | 95,000 | — |
| Jul 30, 2025 | Walker Karin Lofficer: Chief Accounting Officer | Grant | 25,000 | — |
| Jul 30, 2025 | Zago Wagner M.officer: Chief Scientific Officer | Grant | 85,000 | — |
| Jul 30, 2025 | Smith Brandon S.officer: Chief Operating Officer | Grant | 130,000 | — |
| May 16, 2025 | Cobb Paula Kdirector | Grant | 20,183 | $6.88 |
| May 16, 2025 | COLLIER RICHARD Tdirector | Grant | 20,183 | $6.88 |
| May 16, 2025 | Cooke Shanedirector | Grant | 20,183 | $6.88 |
| May 16, 2025 | Dunn William H. Jr.director | Grant | 20,183 | $6.88 |
Source: PRTA SEC Form 4 filings, latest Jun 18, 2026. For informational purposes only — not investment advice.
Institutional activity (13F)
How institutions changed their PRTA positions over the last 6 months (SEC Form 13F).
Increased
134
New positions
49
Reduced
110
Sold out
52
Largest moves
| Institution | Action | Shares | Filed |
|---|---|---|---|
| FMR LLC | Unchanged | 7.6M | May 15, 2026 |
| FMR LLC | Reduced | 7.6M | Feb 17, 2026 |
| RUBRIC CAPITAL MANAGEMENT LP | Increased | 5.0M | May 15, 2026 |
| BLACKROCK, INC. | Increased | 4.6M | May 13, 2026 |
| BLACKROCK, INC. | Increased | 4.1M | Feb 12, 2026 |
| RUBRIC CAPITAL MANAGEMENT LP | Increased | 3.7M | Feb 13, 2026 |
| STATE STREET CORP | Increased | 2.3M | Feb 13, 2026 |
| VANGUARD GROUP INC | Increased | 2.1M | Jan 29, 2026 |
| STATE STREET CORP | Reduced | 1.9M | May 15, 2026 |
| D. E. SHAW & CO., INC. | Increased | 1.8M | May 15, 2026 |
| D. E. SHAW & CO., INC. | Increased | 1.7M | Feb 17, 2026 |
| ADAR1 CAPITAL MANAGEMENT, LLC | Reduced | 1.6M | May 18, 2026 |
| ACADIAN ASSET MANAGEMENT LLC | Increased | 1.5M | May 13, 2026 |
| ARMISTICE CAPITAL, LLC | Reduced | 1.5M | Feb 17, 2026 |
| ADAR1 CAPITAL MANAGEMENT, LLC | Reduced | 1.5M | Feb 18, 2026 |
Source: SEC Form 13F filings. For informational purposes only — not investment advice.