Prothena Corp Public Ltd Co

PRTA

Exchange: Nasdaq
Industry: Pharmaceutical Preparations
SEC CIK: 0001559053

SEC filings (opens in a new tab)

In the last 90 days, Prothena Corp Public Ltd Co insiders filed 6 open-market purchases and 2 sales; 187 institutions reported holding it in 13F filings for Q2 2026, worth $462.7M in total; no superinvestor holds it.

Q2 2026 vs. Q1 2026

How the institutions holding Prothena Corp Public Ltd Co changed between Q1 2026 and Q2 2026.

All holders in Q2 2026 All holders in Q1 2026

13F holders of PRTA: Q1 2026 compared with Q2 2026
Measure	Q1 2026	Of which not filed for Q2 2026	Q2 2026	Change
Holders	186	4	187	+5
Shares	47.3M	325.5K	47.3M	+304.2K (+0.6%)
Value	$459.5M	$3.16M	$462.7M	+$6.28M (+1.4%)

4 institutions that held it in Q1 2026 haven't filed for Q2 2026 yet. Not filing isn't selling, so the changes leave them out.

New holders (28)

Institutions that held Prothena Corp Public Ltd Co at the end of Q2 2026 but not at the end of Q1 2026.

Institutions new to PRTA in Q2 2026
Institution	Shares	Value	% of portfolio
Mackenzie Financial Corp	239,899	$2.35M	0.00%
Diadema Partners LP	149,482	$1.46M	0.52%
State of Wisconsin Investment Board	70,326	$688.5K	0.00%
Engineers Gate Manager LP	41,270	$404.0K	0.01%
Shelton Capital Management	39,472	$386.4K	0.01%
Persistent Asset Partners Ltd	38,100	$373.0K	0.12%
Aquatic Capital Management LLC	25,419	$248.9K	0.01%
Canada Pension Plan Investment Board	24,000	$235.0K	0.00%
Envestnet Asset Management Inc	22,908	$224.3K	0.00%
Headlands Technologies LLC	15,077	$147.6K	0.02%
nVerses Capital, LLC	13,246	$129.7K	0.20%
Wealth Enhancement Advisory Services, LLC	11,156	$103.1K	0.00%
Quadrature Capital Ltd	10,007	$98.0K	0.00%
Cornerstone Select Advisors, LLC	10,000	$97.9K	0.04%
Quantbot Technologies LP	1,611	$15.8K	0.00%
Flagship Wealth Advisors, LLC	1,500	$14.7K	0.00%
Pacer Advisors, Inc.	675	$7.00K	0.00%
Evelyn Partners Group Ltd	199	$1.95K	0.00%
Axiom Investment Management LLC	146	$1.43K	0.00%
Creative Financial Designs Inc	104	$1.02K	0.00%
Quarry LP	90	$881	0.00%
Cary Street Partner Investment Advisory LLC	77	$754	0.00%
Silver Grove Financial Group, Inc.	39	$382	0.00%
Rothschild Investment LLC	10	$98	0.00%
IFG Advisory, LLC	7	$69	0.00%
SJS Investment Consulting Inc.	3	$30	0.00%
Assetmark, Inc	2	$20	0.00%
Coppell Advisory Solutions LLC	12	–	–

Sold out (23)

Institutions that held Prothena Corp Public Ltd Co at the end of Q1 2026 and filed for Q2 2026 without it.

Institutions that sold out of PRTA in Q2 2026
Institution	Shares, Q1 2026	Value, Q1 2026
Armistice Capital, LLC	439,411	$4.27M
Point72 Asset Management, L.P.	399,830	$3.89M
Walleye Capital LLC	277,168	$2.69M
Jane Street Group, LLC	107,926	$1.05M
Y-Intercept (Hong Kong) Ltd	100,805	$979.8K
Jackson Creek Investment Advisors LLC	54,089	$526.0K
Fox Run Management, L.L.C.	35,052	$324.2K
Gsa Capital Partners LLP	32,499	$316.0K
Cornerstone Investment Partners, LLC	30,687	$298.3K
Susquehanna International Group, LLP	17,792	$172.9K
SG Americas Securities, LLC	13,522	$131.0K
Intech Investment Management LLC	11,874	$115.4K
Vontobel Holding Ltd.	10,000	$97.2K
Group One Trading, L.P.	3,416	$33.2K
Simplex Trading, LLC	1,303	$12.7K
Quadrant Capital Group LLC	841	$8.18K
Aster Capital Management (DIFC) Ltd	256	$3.17K
Johnson Financial Group, Inc.	151	$1.47K
Keating Financial Advisory Services, Inc.	76	$739
Root Financial Partners, LLC	38	$369
Advisory Services Network, LLC	30	$292
MAI Capital Management	10	$98
Wealth Preservation Advisors, LLC	1	$10

Not filed for Q2 2026 yet (4)

Institutions that held Prothena Corp Public Ltd Co at the end of Q1 2026 and haven't filed a 13F for Q2 2026. Not filing isn't selling, so they aren't counted as sold out.

Institutions holding PRTA in Q1 2026 that haven't filed for Q2 2026
Institution	Shares, Q1 2026	Value, Q1 2026
Deeter Investments LLP	300,000	$2.92M
Skopos Labs, Inc.	14,993	$145.7K
CWM, LLC	10,276	$99.9K
Evelyn Partners Investment Management LLP	199	$1.93K