Prothena Corp Public Ltd Co (PRTA) Institutional Ownership

Institutions by Trading Activity

Ownership Statistics

53,830,902Shares Outstanding

400,744Shares held by institutions

$3,590,666Value of institutional holdings

88.33%Institutional ownership %

14.65%Shares Changed QoQ

175No. of institutional investors

Shares Owned by Institutions

Shares Purchased/Sold by Institutions

Ownership Summary

A total of 175 institutions have reported a stake in Prothena Corp Public Ltd Co (NASDAQ:PRTA) as of December 2025, according to recent 13F filings with the SEC.

The collective stake of institutional investors in Prothena Corp Public moved to 88.3% in December 2025, a shift up from the 79.9% reported for September 2025.
The company experienced a 14.65% quarterly change in institutional shares held, alongside an increase of 2.94% in total owners annually.
Among the 175 institutional holders of Prothena Corp Public, 85 added to their stakes while 55 trimmed their positions and 35 held steady.
The total number of shares held by institutions in Prothena Corp Public increased to 47.55Mn as of December 2025, a net change of up by 6.08Mn shares quarter on quarter, and down 6.16Mn shares year over year.
FMR LLC continues to be the largest institutional holder of Prothena Corp Public as of December 31, 2025, with a position of 7.55Mn shares, representing 14.03% of the company's outstanding stock.
Among the most significant buyers of Prothena Corp Public during December 2025 were Rubric Capital Management LP (2.14Mn), STATE STREET CORP (1.37Mn), GOLDMAN SACHS GROUP INC (582.11K), BlackRock, Inc. (509.04K), MORGAN STANLEY (447.10K).
Leading sellers of Prothena Corp Public stock in December 2025 included JPMORGAN CHASE & CO (565.81K), MILLENNIUM MANAGEMENT LLC (521.72K), ARROWSTREET CAPITAL, LIMITED PARTNERSHIP (356.19K), FMR LLC (350.00K), ARMISTICE CAPITAL, LLC (324.00K).
The top 10 institutional holders of Prothena Corp Public for the quarter ending December 2025 included FMR LLC (7.55Mn), BlackRock, Inc. (4.11Mn), Rubric Capital Management LP (3.68Mn), STATE STREET CORP (2.27Mn), VANGUARD GROUP INC (2.14Mn), D. E. Shaw & Co., Inc. (1.68Mn), ARMISTICE CAPITAL, LLC (1.50Mn), ADAR1 Capital Management, LLC (1.46Mn), ACADIAN ASSET MANAGEMENT LLC (1.44Mn), Palo Alto Investors LP (1.32Mn).

175 Institutional Holders

400,744 Total Shares Held

Rows:

Download Data

Owner Name	Date	Shares Held	Change (QoQ)	Change (%)	Value (USD)
FMR LLC	31 Dec, 2025	7,551,218	-350,000	-4.43%	$72,114,132.00
BlackRock, Inc.	31 Dec, 2025	4,107,459	509,042	14.15%	$39,226,235.00
Rubric Capital Management LP	31 Dec, 2025	3,677,331	2,136,958	138.73%	$35,118,511.00
STATE STREET CORP	31 Dec, 2025	2,267,802	1,366,764	151.69%	$21,657,509.00
VANGUARD GROUP INC	31 Dec, 2025	2,140,909	91,060	4.44%	$20,445,681.00
D. E. Shaw & Co., Inc.	31 Dec, 2025	1,681,369	365,951	27.82%	$16,057,074.00
ARMISTICE CAPITAL, LLC	31 Dec, 2025	1,500,000	-324,000	-17.76%	$14,325,000.00
ADAR1 Capital Management, LLC	31 Dec, 2025	1,457,764	-11,334	-0.77%	$13,921,646.00
ACADIAN ASSET MANAGEMENT LLC	31 Dec, 2025	1,437,358	198,116	15.99%	$13,720.00
Palo Alto Investors LP	31 Dec, 2025	1,320,510	-3,518	-0.27%	$12,610,871.00
MORGAN STANLEY	31 Dec, 2025	1,246,775	447,101	55.91%	$11,906,710.00
GEODE CAPITAL MANAGEMENT, LLC	31 Dec, 2025	1,063,069	43,586	4.28%	$10,154,236.00
JACOBS LEVY EQUITY MANAGEMENT, INC	31 Dec, 2025	978,011	101,483	11.58%	$9,340,005.00
FEDERATED HERMES, INC.	31 Dec, 2025	974,367	281,549	40.64%	$9,305,205.00
GOLDMAN SACHS GROUP INC	31 Dec, 2025	935,333	582,112	164.80%	$8,932,430.00
CITADEL ADVISORS LLC	31 Dec, 2025	912,382	145,277	18.94%	$8,713,248.00
Point72 Asset Management, L.P.	31 Dec, 2025	860,018	213,272	32.98%	$8,213,172.00
DIMENSIONAL FUND ADVISORS LP	31 Dec, 2025	775,207	-31,781	-3.94%	$7,402,857.00
Nuveen, LLC	31 Dec, 2025	759,107	90,817	13.59%	$7,249,472.00
JANE STREET GROUP, LLC	31 Dec, 2025	699,751	-179,441	-20.41%	$6,682,622.00

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