Institutional Ownership
Prothena Corp PLC
CUSIP G72800108SHSQ1 2026
13D / 13G Filings
53
Schedule 13D/13G on record
Beneficial Filers
18
Distinct reporting persons
Largest Stake
25.7%
Max % of class reported
Institutional Holders
179
13F filers (latest quarter)
Beneficial Owners — Schedule 13D / 13G
53 filings · latest Feb 13, 2026
| # | Filed | Reporting Person | Form | % of Class | Shares | Filing |
|---|---|---|---|---|---|---|
| 1 | Feb 13, 2026 | Rubric Capital Management LP | 13G | 6.8% | 3.68M | SEC |
| 2 | Nov 14, 2025 | Adar1 Capital Management, LLC | 13G/A | 13.0% | 1.47M | SEC |
| 3 | Nov 12, 2025 | Fennell Todd W. | 13G/A | 8.4% | 4.50M | SEC |
| 4 | Nov 12, 2025 | Scully William P | 13G/A | 9.8% | 5.28M | SEC |
| 5 | Oct 17, 2025 | Blackrock, Inc. | 13G/A | 5.7% | 3.09M | SEC |
| 6 | Aug 14, 2025 | Adar1 Capital Management, LLC | 13G | 13.0% | 3.38M | SEC |
| 7 | Aug 14, 2025 | Logos Global Management LP | 13G/A | — | — | SEC |
| 8 | Aug 14, 2025 | T. Rowe Price Associates, Inc. | 13G/A | 0.1% | 71.0K | SEC |
| 9 | Aug 13, 2025 | Fennell Todd W. | 13G/A | 8.1% | 4.35M | SEC |
| 10 | Aug 13, 2025 | Scully William P | 13G/A | 9.9% | 5.35M | SEC |
43 more beneficial-ownership filings on Premium
See the full Schedule 13D/13G history for Prothena Corp PLC.
Unlock full historyTop Institutional Holders (13F)
Largest reported positions · latest quarter
| # | Fund | Shares | Value |
|---|---|---|---|
| 1 | Fmr LLC | 7.55M | $73.40M |
| 2 | Rubric Capital Management LP | 5.00M | $48.60M |
| 3 | Blackrock, Inc. | 4.64M | $45.14M |
| 4 | State Street Corp | 1.94M | $18.84M |
| 5 | D. E. Shaw & Co., Inc. | 1.76M | $17.14M |
| 6 | Adar1 Capital Management, LLC | 1.58M | $15.37M |
| 7 | Morgan Stanley | 1.23M | $11.96M |
| 8 | Palo Alto Investors LP | 1.21M | $11.75M |
| 9 | Two Sigma Investments, LP | 1.21M | $11.72M |
| 10 | Geode Capital Management, LLC | 1.10M | $10.68M |