ACADIAN ASSET MANAGEMENT LLC

Position in PRTA — Prothena Corp Public Ltd Co

CIK 916542 Boston, MA

Position in PRTA

as of Jun 30, 2026 · filed Aug 13, 2026 Compact

Position Value

$19,684,214

+$4,641,611 QoQ

Shares Held

2,010,645

+29.9% QoQ

Ownership

3.92%

of shares outstanding

% of Portfolio

0.02%

of 13F equity value

Holder Rank

of 187 holders

Holding Since

Mar 2020

13 quarters on record

Voting authority Sole 100% Shared 0% None 0%

Healthcare · as of Jun 30, 2026

ACADIAN ASSET MANAGEMENT LLC holds $731,256,203 across 167 Biotechnology names. PRTA ranks #8 (2.7% of the industry book) .

#	Ticker	Company	Shares	Value (USD)
1	INCY	Incyte Corp	1,664,999	$188,744,286
2	REGN	Regeneron Pharmaceuticals, Inc.	157,440	$98,170,137
3	IMCR	Immunocore Holdings plc	1,209,894	$38,414,134
4	RIGL	Rigel Pharmaceuticals Inc	591,686	$23,146,756
5	EXEL	Exelixis, Inc.	421,444	$22,930,768
6	VRTX	Vertex Pharmaceuticals Inc / Ma	42,122	$20,923,261
7	TBPH	Theravance Biopharma, Inc.	1,174,910	$19,973,470
8	PRTA	Prothena Corp Public Ltd Co This page	2,010,645	$19,684,214

13 filing rows on record

Report Date	Value (USD)	Shares	Change	Type	Discretion	Filed
2026-06-30	$19,684,214	2,010,645	+29.9%	Shares	Defined	2026-08-13
2026-03-31	$15,042,603	1,547,593	+7.7%	Shares	Defined	2026-05-13
2025-12-31	$13,726,768	1,437,358	+16.0%	Shares	Defined	2026-02-10
2025-09-30	$12,095,001	1,239,242	+21.7%	Shares	Defined	2025-11-13
2025-06-30	$6,180,334	1,018,177	+22204.0%	Shares	Defined	2025-08-07
2024-12-31	$63,225	4,565	-42.7%	Shares	Defined	2025-02-11
2021-12-31	$393,273	7,961	+456.7%	Shares	Defined	2022-02-10
2021-09-30	$101,858	1,430	-97.8%	Shares	Defined	2021-11-12
2021-03-31	$1,659,000	66,043	-62.6%	Shares	Defined	2021-05-11
2020-12-31	$2,119,032	176,439	-16.0%	Shares	Defined	2021-02-11
2020-09-30	$2,098,069	210,017	-7.1%	Shares	Defined	2020-11-09
2020-06-30	$2,363,499	225,956	+7.5%	Shares	Defined	2020-08-12
2020-03-31	$2,249,717	210,254	—	Shares	Defined	2020-05-11
No filing history on record for this holder in this stock.