SEC ownership of PROTHENA CORP PUBLIC LTD CO

Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001559053.

Comparable stake leader

FMR LLC

Disclosed value leader

FMR LLC

Comparable rows

50/50

Latest evidence

28 Jul 2026

Top shareholders Insider holders Latest transactions
Public ticker
PRTA on Nasdaq
Parsed ownership sources
13F, 13D/G, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
Largest SEC-reported holder
FMR LLC
Ranking: Comparable ownership first, then disclosed value
Ownership snapshot CIK-linked ownership evidence from parsed SEC filings. 3 signals
Comparable ownership rows
50 of 50
Meaning: Rows with safely comparable ownership %
Latest 13D/G holder
FMR LLC
Source: Latest parsed Schedule 13D/G stake
Latest parsed ownership date
28 Jul 2026
Freshness: Most recent filing date in this holder set
Issuer Names, identifiers, and filing context for this profile. 2 identity fields
Issuer CIK
0001559053
Issuer location
Dublin 2, Ireland

Ownership snapshot

Top shareholders of PROTHENA CORP PUBLIC LTD CO (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.

Comparable stake leader
FMR LLC
Disclosed value leader
FMR LLC
Comparable rows
50/50
Latest evidence
28 Jul 2026
13F 13D/G 3/4/5 Lead comparable stake: 14% 13D/G row: FMR LLC Showing 1-8 of 50 holder rows.

Quick read

FMR LLC leads the comparable SEC ownership view at 14%.

50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.

Open SEC evidence Opens FMR LLC's linked filing trail.
Comparable ownership Top 5
FMR LLC 14%
William P. Scully 10%
Rubric Capital Management LP 9.3%
Fennell Todd W. 8.4%
BlackRock, Inc. 6.9%

Ownership % is shown only when SEC disclosures are safely comparable across share classes.

Detailed SEC evidence table Showing 1-8 of 50 holder rows
Holder Evidence Ownership % Position 12M Net Δ As of
FMR LLC
13F 13D/G
Company
13F 13D/G
14%
from 13D/G
$73,397,839
7,551,218 shares
 — 31 Mar 2026
William P. Scully
13D/G 3/4/5
SCULLY WILLIAM P · 10%+ Owner
13D/G 3/4/5
10%
$53,949,825
5,378,846 shares
 +$972,910 07 May 2026
Rubric Capital Management LP
13D/G 13F
Company
13D/G 13F
9.3%
$50,150,000
5,000,000 shares
 +$13,266,370 31 Mar 2026
Fennell Todd W.
13D/G
13D/G
8.4%
$43,879,457
4,495,846 shares
 +$1,415,200 30 Sep 2025
BlackRock, Inc.
13F 13D/G
Company
13F 13D/G
6.9%
from 13D/G
$45,141,233
4,644,160 shares
 — 31 Mar 2026
ADAR1 Capital Management, LLC
13F 13D/G
Company
13F 13D/G
2.7%
from 13D/G
$15,371,626
1,581,443 shares
 — 31 Mar 2026
WELLINGTON MANAGEMENT GROUP LLP
13D/G
13D/G
0.2%
$821,299
108,208 shares
 -$38,122,050 30 May 2025
PRICE T ROWE ASSOCIATES INC /MD/
13F 13D/G
Company · T. Rowe Price Associates, Inc.
13F 13D/G
0.1%
from 13D/G
$930,000
95,649 shares
 — 31 Mar 2026
How to read this table

Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.

Forms 3/4/5 flow

Insider trading overview

Net insider flow leans to buying over the last 12 months. Net value: +$2,961,135.

Buys
$3,097,110
Insiders: 1
Sells
$135,975
Insiders: 2
Net
+$2,961,135
Shares: +328,952
Window
Last 12 months
4 rolling buckets
Buy value Sell value
Shares: 345,000 Shares: 16,048
Window (months) Buy shares Sell shares Buy value Sell value Net value
0-3 345,000 16,048 $3,097,110 $135,975 +$2,961,135
3-6 0 0 $0 $0 $0
6-9 0 0 $0 $0 $0
9-12 0 0 $0 $0 $0

Reporting owners

Insider holders from Forms 3/4/5

Showing 1-20 of 26 reporting-owner rows connected to PROTHENA CORP PUBLIC LTD CO. Open a relationship link for the CIK-to-CIK filing trail.

Rows
26
Largest Forms 3/4/5 holder
EcoR1 Capital, LLC
Net 12M change
+$2,961,136
Latest report
28 Jul 2026
Name Relationship Holdings Value Past Year Net Change Change % Valuation Report Date
EcoR1 Capital, LLC 10%+ Owner $40,544,618 Filing P/S 02 May 2025
William P. Scully 10%+ Owner $7,950,022 +$3,097,110 +64% Mixed 16 Jun 2026
Gene G. Kinney President and CEO, Director $673,483 Median 28 Jul 2026
Brandon S. Smith Chief Operating Officer $509,080 Median 28 Jul 2026
Michael J. Malecek Chief Legal Officer $485,600 Mixed 03 Mar 2026
Anne E. Kingston Chief Strategy Officer $472,635 -$64,919 -12% Filing P/S 28 Jul 2026
Chad J. Swanson Chief Development Officer $398,776 Median 28 Jul 2026
Tran B. Nguyen Chief Strategy Officer and CFO $393,606 Median 28 Jul 2026
Wagner M. Zago Chief Scientific Officer $332,860 Median 28 Jul 2026
Michael J. Isaacs General Counsel & Company Sec. $302,870 -$71,055 -19% Filing P/S 28 Jul 2026
Karin L. Walker Chief Accounting Officer $97,900 Median 28 Jul 2026
Radhika Tripuraneni Chief Development Officer Mixed 23 Feb 2022
Dennis J. Selkoe Director Mixed 15 May 2026
Karl Anders O Harfstrand Director Mixed 17 May 2023
Richard T. Collier Director Mixed 15 May 2026
Christopher S. Henney Director Mixed 14 Jul 2021
Lars G. Ekman Director Mixed 15 May 2026
Paula K. Cobb Director Mixed 14 May 2025
Carol D. Karp Chief Regulatory Officer Mixed 05 Mar 2025
William H. Dunn Jr. Director Mixed 15 May 2026

Recent insider transactions for PROTHENA CORP PUBLIC LTD CO

Showing up to 300 recent insider transactions from the last 12 months.

Insider Symbol Class Transaction % SEC-reported value SEC-reported price Shares Shares owned Date Ownership
Anne E. Kingston PRTA Ordinary Shares, par value $0.01 per share Sale -12.1% $64,919 $8.47 -7,662 55,782 29 Jul 2026 Direct
Michael J. Isaacs PRTA Ordinary Shares, par value $0.01 per share Sale -19% $71,055 $8.47 -8,386 35,745 29 Jul 2026 Direct
Wagner M. Zago PRTA Ordinary Shares, par value $0.01 per share Disposed to Issuer -60% -51,000 34,000 28 Jul 2026 Direct
Wagner M. Zago PRTA Ordinary Shares, par value $0.01 per share Options Exercise 150% 51,000 85,000 28 Jul 2026 Direct
Wagner M. Zago PRTA Restricted Stock Units Options Exercise -100% -51,000 0 28 Jul 2026 Direct
Karin L. Walker PRTA Ordinary Shares, par value $0.01 per share Disposed to Issuer -60% -15,000 10,000 28 Jul 2026 Direct
Karin L. Walker PRTA Ordinary Shares, par value $0.01 per share Options Exercise 150% 15,000 25,000 28 Jul 2026 Direct
Karin L. Walker PRTA Restricted Stock Units Options Exercise -100% -15,000 0 28 Jul 2026 Direct
Chad J. Swanson PRTA Ordinary Shares, par value $0.01 per share Tax liability -7.84% -3,467 40,733 28 Jul 2026 Direct
Chad J. Swanson PRTA Ordinary Shares, par value $0.01 per share Disposed to Issuer -48% -40,800 44,200 28 Jul 2026 Direct
Chad J. Swanson PRTA Ordinary Shares, par value $0.01 per share Options Exercise 150% 51,000 85,000 28 Jul 2026 Direct
Chad J. Swanson PRTA Restricted Stock Units Options Exercise -100% -51,000 0 28 Jul 2026 Direct
Brandon S. Smith PRTA Ordinary Shares, par value $0.01 per share Disposed to Issuer -60% -78,000 52,000 28 Jul 2026 Direct
Brandon S. Smith PRTA Ordinary Shares, par value $0.01 per share Options Exercise 150% 78,000 130,000 28 Jul 2026 Direct
Brandon S. Smith PRTA Restricted Stock Units Options Exercise -100% -78,000 0 28 Jul 2026 Direct
Tran B. Nguyen PRTA Ordinary Shares, par value $0.01 per share Disposed to Issuer -58.6% -57,000 40,205 28 Jul 2026 Direct
Tran B. Nguyen PRTA Ordinary Shares, par value $0.01 per share Options Exercise 141.8% 57,000 97,205 28 Jul 2026 Direct
Tran B. Nguyen PRTA Restricted Stock Units Options Exercise -100% -57,000 0 28 Jul 2026 Direct
Gene G. Kinney PRTA Ordinary Shares, par value $0.01 per share Disposed to Issuer -55% -84,000 68,793 28 Jul 2026 Direct
Gene G. Kinney PRTA Ordinary Shares, par value $0.01 per share Options Exercise 122.1% 84,000 152,793 28 Jul 2026 Direct
Gene G. Kinney PRTA Restricted Stock Units Options Exercise -100% -84,000 0 28 Jul 2026 Direct
Anne E. Kingston PRTA Ordinary Shares, par value $0.01 per share Tax liability -5.23% -3,498 63,444 28 Jul 2026 Direct
Michael J. Isaacs PRTA Ordinary Shares, par value $0.01 per share Tax liability -9.61% -4,694 44,131 28 Jul 2026 Direct
William P. Scully PRTA Ordinary Shares, par value $0.01 per share Purchase 2.72% $157,990 $7.90 20,000 756,000 16 Jun 2026 Direct
William P. Scully PRTA Ordinary Shares, par value $0.01 per share Gift -30.6% -325,000 736,000 15 Jun 2026 Direct
William P. Scully PRTA Ordinary Shares, par value $0.01 per share Purchase 13.4% $1,021,225 $8.17 125,000 1,061,000 11 Jun 2026 Direct
William P. Scully PRTA Ordinary Shares, par value $0.01 per share Purchase 5.64% $465,295 $9.31 50,000 936,000 04 Jun 2026 Direct
William P. Scully PRTA Ordinary Shares, par value $0.01 per share Purchase 5.98% $471,300 $9.43 50,000 886,000 02 Jun 2026 Direct
William P. Scully PRTA Ordinary Shares, par value $0.01 per share Purchase 13.6% $981,300 $9.81 100,000 836,000 22 May 2026 Direct
Daniel G. Welch PRTA Stock Option (Right to Buy) Award 27,000 27,000 15 May 2026 Direct
Dennis J. Selkoe PRTA Stock Option (Right to Buy) Award 27,000 27,000 15 May 2026 Direct
Lars G. Ekman PRTA Stock Option (Right to Buy) Award 27,000 27,000 15 May 2026 Direct
William H. Dunn Jr. PRTA Stock Option (Right to Buy) Award 27,000 27,000 15 May 2026 Direct
Shane Cooke PRTA Stock Option (Right to Buy) Award 27,000 27,000 15 May 2026 Direct
Richard T. Collier PRTA Stock Option (Right to Buy) Award 27,000 27,000 15 May 2026 Direct
Anne E. Kingston PRTA Stock Option (Right to Buy) Award 100,000 100,000 10 Apr 2026 Direct
Wagner M. Zago PRTA Stock Option (Right to Buy) Award 190,000 190,000 03 Mar 2026 Direct
Karin L. Walker PRTA Stock Option (Right to Buy) Award 150,000 150,000 03 Mar 2026 Direct
Chad J. Swanson PRTA Stock Option (Right to Buy) Award 190,000 190,000 03 Mar 2026 Direct
Brandon S. Smith PRTA Stock Option (Right to Buy) Award 190,000 190,000 03 Mar 2026 Direct
Tran B. Nguyen PRTA Stock Option (Right to Buy) Award 230,000 230,000 03 Mar 2026 Direct
Michael J. Malecek PRTA Stock Option (Right to Buy) Award 190,000 190,000 03 Mar 2026 Direct
Gene G. Kinney PRTA Stock Option (Right to Buy) Award 520,000 520,000 03 Mar 2026 Direct
* marks a reported price that did not pass the local price check.
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