Prothena Corporation plc (PRTA)
Nasdaq: PRTA · Pharmaceutical Preparations · Dublin 2, IE · filing with the SEC since 2012
Who owns Prothena Corporation plc
As filed with the SECHolders of 5% or more
5
Fmr LLC holds 13.8% of COMMON STOCK, as its SCHEDULE 13G/A filed Aug 6, 2026 says.
Directors and officers
15
report now, of 31 people on the record since 2012. Their holdings as a group are not read here.
Institutions as a whole
n/a
The record does not read the share held by managers that file Form 13F, so none is printed and no split of the rest is estimated. What it holds is the 5 named at left.
Holders of 5% or moreshare of the class, as filed
Fmr LLC
SCHEDULE 13G/A · filed Aug 6, 2026 · COMMON STOCK
Scully William P
SCHEDULE 13G/A · filed May 11, 2026 · Ordinary Shares, $0.01 par value · 9.8% in Nov 12, 2025
Fennell Todd W.
SCHEDULE 13G/A · filed Aug 19, 2026 · Ordinary Shares, $0.01 par value · 9.8% in Aug 14, 2026
Rubric Capital Management LP
SCHEDULE 13G/A · filed May 15, 2026 · Ordinary Shares, par value $0.01 per share · 6.83% in Feb 13, 2026
Blackrock, Inc.
SCHEDULE 13G/A · filed Jul 29, 2026 · Common Stock · 5.7% in Oct 17, 2025
ADAR1 Capital Management, LLC
SCHEDULE 13G/A · filed Nov 14, 2025 · Ordinary Shares, par value $0.01 per share · reported falling below 5%, from 6.3% in Aug 14, 2025
Wellington Management Group LLP
SCHEDULE 13G/A · filed Jun 5, 2025 · Ordinary Shares · reported falling below 5%, from 9.5% in Feb 10, 2025
T. Rowe Price Associates, Inc.
SCHEDULE 13G/A · filed Aug 14, 2025 · COMMON STOCK · reported falling below 5%
Logos Global Management LP
SCHEDULE 13G/A · filed Aug 14, 2025 · Ordinary Shares · reported falling below 5%, from 5.5% in Jun 4, 2025
EcoR1 Capital, LLC
SCHEDULE 13D/A · filed May 29, 2025 · Ordinary Shares · reported falling below 5%, from 9.9% in May 6, 2025
What PRTA reports owning in othersstakes of 5% or more, and other ties
6 subsidiaries in 2 countries, from the list filed with the 10-K filed Feb 27, 2026.
Insider tradesForm 4
2sales
0purchases
2sales on a scheduled plan
2people selling
$100,000sold, in dollars
$0bought, in dollars
Open-market trades on Form 4 from Nov 10, 2025 to Nov 10, 2026. A scheduled plan is a selling program set in advance under SEC rule 10b5-1. The trades are listed as filed and do not feed the grade.
By calendar yearSoldBought
2026 runs to Nov 10, 2026. Dollars as filed, summed by the transaction date.
People who traded in the window3 of 34 on the roster
| Person | Role as filed | Sales | Sold | On a plan | Buys | Bought |
|---|---|---|---|---|---|---|
| Kingston Anne Evans | Chief Strategy Officer | 1 | $100,000 | 1 | 0 | $0 |
| Isaacs Michael John | General Counsel & Company Sec. | 1 | $100,000 | 1 | 0 | $0 |
| Scully William P | 10% owner | 0 | $0 | 0 | 20 | $13.3M |