How many institutions held PRTA - PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, $0.01 par value in Q1 2026?

186 institutional investors reported PRTA - PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, $0.01 par value for Q1 2026. Use the holders table for investor-level position and value details.

PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, $0.01 par value (PRTA)

Q: What does CUSIP G72800108 represent in this 13F holders report?

CUSIP G72800108 is the security identifier for PRTA - PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, $0.01 par value used to aggregate holder disclosures.

CUSIP: G72800108

Q1 2026 13F Holders as of 31 Mar 2026

Security type / class: Equity / Ordinary Shares, $0.01 par value
Total 13F shares: 47,280,954
Total 13F value: $459,532,437
Share change: -21,270
Put/Call ratio: 47%
SEC-reported price per share: $9.72
Number of holders: 186
Value change: +$45,325
Number of buys: 92
Number of sells: 71
Shares outstanding: 51,459,275

Security key

G72800108

Report period

Q1 2026

Institutions

186

Top holders

PRTA full security history Ownership snapshot Full 13F holder table Newer quarter: Q3 2026 PROTHENA CORP PUBLIC LTD CO SEC filings PROTHENA CORP PUBLIC LTD CO company facts

Broader feeds

Latest 13F filings Latest 13D/G filings Investors directory

Reporting periods

Holder history for CUSIP G72800108

Newer quarter: Q3 2026

Recent filing periods:

Q3 2026

Ownership snapshot

Top reported holders of PRTA - PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, $0.01 par value (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

Rubric Capital Management LP

Disclosed value leader

FMR LLC

Comparable rows

15/15

Latest evidence

31 Mar 2026

13D/G 13F 3/4/5 Lead comparable stake: 9.3% 13D/G row: Rubric Capital Management LP Showing 1-6 of 15 holder rows.

Quick read

Rubric Capital Management LP leads the comparable SEC ownership view at 9.3%.

15 of 15 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 Rubric Capital Management LP's linked filing trail.

Comparable ownership Top 5

Rubric Capital Management LP 9.3%

ADAR1 Capital Management, LLC 2.7%

WELLINGTON MANAGEMENT GROUP LLP 0.2%

PRICE T ROWE ASSOCIATES INC /MD/ 0.1%

EcoR1 Capital, LLC 10%

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

Detailed SEC evidence table Showing 1-6 of 15 holder rows

Holder	Evidence	Ownership %	Position	12M Net Δ	As of
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
ADAR1 Capital Management, LLC	13D/G 13F Company 13D/G 13F	2.7%	$14,338,396 1,469,098 shares	-$18,601,691	30 Sep 2025
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	$779,000 81,515 shares	—	31 Dec 2025
EcoR1 Capital, LLC	3/4/5 10%+ Owner 3/4/5	10%	$40,544,618 5,304,596 shares	—	02 May 2025
FMR LLC	13F Company 13F	15%	$72,114,132 7,551,218 shares	—	31 Dec 2025

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.

13F holder rows

Institutional holders as of Q1 2026

Investor-level positions for this CUSIP, loaded as an interactive table.

Institutions

186

47,280,954

Rows available

186

Investor	Option	Weight %	Change %	SEC-reported value	* Price	Shares	Share Change	Activity	Report Period

^* SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that did not pass the local price check.

Compare Q1 2026 vs Q1 2026 Across Filers

Q1 2026 holders

186

Q1 2026 holders

186

Holder diff

Investor	Q1 2026 Shares	Q1 2026 Shares	Share Diff	Share Chg %	Q1 2026 value	Q1 2026 value	Value change	Value Chg %

Trend: ostatnie 8 kwartałów (+ wybrane okresy porównania).

Quarterly Holders Trend

Quarterly Value Trend

Quarterly Shares Trend