Companies / Prothena Corp Public Ltd Co
Prothena Corp Public Ltd Co
Nasdaq: PRTAForeign · IFRSCIK 1559053DUBLIN 2
Financials · FY2025
Ownership
51.3M shares outstanding · as of Jul 30, 2026
Ownership
| Institutions | 97.38% | 49,990,028 |
| Public float | 2.62% | 1,346,946 |
% of common shares outstanding (exact, from the latest cover-page filing). Institutions are quarterly 13F snapshots; insiders reflect current officers & directors.
Insiders 11
View all →| Insider | % of shares | Shares |
|---|---|---|
Collier Richard TDirector | — | — |
Ekman LarsDirector | — | — |
Kinney Gene G.CEOPresident and CEO · Director | — | — |
Malecek Michael JChief Legal Officer | — | — |
Nguyen TranChief Strategy Officer and CFO | — | — |
Scully William P10% owner | — | — |
Smith Brandon S.Chief Operating Officer | — | — |
Swanson Chad J.Chief Development Officer | — | — |
Walker Karin LChief Accounting Officer | — | — |
Welch Daniel GDirector | — | — |
Institutional holders 188
View all →| Holder | Value | % of shares |
|---|---|---|
| $72.11M | 14.71% | |
| $47.66M | 9.48% | |
| $35.12M | 7.16% | |
| $23.43M | 4.66% | |
| $20.45M | 4.17% | |
| $17.14M | 3.43% | |
| $14.32M | 2.92% | |
| $13.92M | 2.84% | |
| $11.91M | 2.43% | |
| $11.75M | 2.35% |
Activity
Jun 30, 2026View all →
InsidersInstitutions
Who's accumulating and trimming this stock (13F).| Date | Actor | Action | Security | Value | Shares Δ | Position after | Impact |
|---|---|---|---|---|---|---|---|
| Q2 2025 as of | Boxer Capital Management, LLC 13F manager | Exit | — | $-8.54M | -690K -100.00% | — | medium |
| Q2 2026 as of | BlackRock, Inc. 13F manager | Add | — | $7.45M | +760K +18.51% | 4,867,955 9.48% of shares | medium |
| Q1 2026 as of | Two Sigma Investments, LP 13F manager | Add | — | $5.21M | +536K +79.96% | 1,205,978 2.35% of shares | medium |
| Q1 2026 as of | Arrowstreet Capital, Limited Partnership 13F manager | Exit | — | $-2.85M | -298K -100.00% | — | low |
| Q1 2026 as of | Penbrook Management LLC 13F manager | New | — | $2.64M | +272K | 271,720 0.53% of shares | low |
| Q1 2024 as of | Barclays PLC 13F manager | Trim | — | $-2.09M | -84K -59.10% | 58,332 0.11% of shares | low |
| Q4 2023 as of | Barclays PLC 13F manager | Add | — | $2.06M | +57K +65.75% | 142,607 0.28% of shares | low |
| Q1 2026 as of | Renaissance Technologies LLC 13F manager | Add | — | $1.67M | +172K +39.49% | 607,515 1.18% of shares | low |
5%+ ownership events
Schedule 13D / 13G
| Filer | Stance | % of class |
|---|---|---|
| Rubric Capital Management LP | Passive13G | — |
| Scully William P | Passive13G/A | — |
Securities
via CUSIP / OpenFIGI
| Symbol | Type | CUSIP |
|---|---|---|
| PRTA | — | G72800108 |