Prothena Corp Public Ltd Co has 16 Schedule 13D or 13G filings on record since 2025-08-13. 5 holders' latest filing reports 5% or more of ordinary shares, $0.01 par value. Each figure below is the holder's own, as filed, with the filing linked.
Holders
| Holder | Percent | Shares | Latest | Event date |
|---|---|---|---|---|
| Fmr LLC | 13.8% | 7,199,218 | SCHEDULE 13G/A, 2026-08-06 | 2026-06-30 |
| Scully William P | 10.3% | 5,378,846 | SCHEDULE 13G/A, 2026-05-11 | 2026-05-07 |
| Fennell Todd W. | 10.2% | 5,248,846 | SCHEDULE 13G/A, 2026-08-19 | 2026-08-18 |
| Rubric Capital Management LP | 9.29% | 5,000,000 | SCHEDULE 13G/A, 2026-05-15 | 2026-03-31 |
| BlackRock, Inc. | 6.9% | 3,587,480 | SCHEDULE 13G/A, 2026-07-29 | 2026-06-30 |
| ADAR1 Capital Management, LLC | 2.7% | 1,469,098 | SCHEDULE 13G/A, 2025-11-14 | 2025-09-30 |
| T. Rowe Price Associates, Inc. | 0.1% | 71,047 | SCHEDULE 13G/A, 2025-08-14 | 2025-06-30 |
| Logos Global Management LP | 0% | 0 | SCHEDULE 13G/A, 2025-08-14 | 2025-06-30 |
Timeline
| Filed | Holder | Percent | Filing |
|---|---|---|---|
| 2025-08-13 | Scully William P | 9.9% | SCHEDULE 13G/A |
| 2025-08-13 | Fennell Todd W. | 8.1% | SCHEDULE 13G/A |
| 2025-08-14 | T. Rowe Price Associates, Inc. | 0.1% | SCHEDULE 13G/A |
| 2025-08-14 | Logos Global Management LP | 0% | SCHEDULE 13G/A |
| 2025-08-14 | ADAR1 Capital Management, LLC | 6.3% | SCHEDULE 13G |
| 2025-10-17 | BlackRock, Inc. | 5.7% | SCHEDULE 13G/A |
| 2025-11-12 | Scully William P | 9.8% | SCHEDULE 13G/A |
| 2025-11-12 | Fennell Todd W. | 8.4% | SCHEDULE 13G/A |
| 2025-11-14 | ADAR1 Capital Management, LLC | 2.7% | SCHEDULE 13G/A |
| 2026-02-13 | Rubric Capital Management LP | 6.83% | SCHEDULE 13G |
| 2026-05-11 | Scully William P | 10.3% | SCHEDULE 13G/A |
| 2026-05-15 | Rubric Capital Management LP | 9.29% | SCHEDULE 13G/A |
| 2026-07-29 | BlackRock, Inc. | 6.9% | SCHEDULE 13G/A |
| 2026-08-06 | Fmr LLC | 13.8% | SCHEDULE 13G/A |
| 2026-08-14 | Fennell Todd W. | 9.8% | SCHEDULE 13G/A |
| 2026-08-19 | Fennell Todd W. | 10.2% | SCHEDULE 13G/A |
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Where this comes from
Anyone who comes to own more than 5% of a class of a listed company's voting shares has to tell the SEC. A holder who may seek to change or influence the company files Schedule 13D, and has to say in Item 4, "Purpose of Transaction", what it intends to do. A holder with no such intent, such as many index and passive funds, may file the shorter Schedule 13G. Both are amended when the stake changes, including when it falls below 5%.
Every row here is one of those filings, linked to the filing itself. Percentages and share counts are exactly as the holder filed them, for the holder the filing names; an amendment showing a lower figure is shown as filed. Item 4 text is quoted word for word. Where a 13D's Item 4 contains a sentence stating a definite intent to influence the company, that sentence is marked and quoted; the page does not describe the holder or its motives beyond the words it filed. Nothing here is investment advice.