PRTA

PRTA — Who Owns This Stock? 13F Breakdown

Prothena Corporation plc

-$2.4M

Net Activity

Institutions Holding

186

Popularity Rank

#3079

Avg Weight

0.08%

Total Value

$457.4M

Ownership Trend

186 institutions currently hold PRTA, with 91 net buyers and 76 net sellers this quarter.

Institutional Moves

Institutional Moves (Q1 2026)

Neutral

Based on recent trading activity

Net Selling Institutions

76

Net Buying Institutions

91

Key Holders

Key Holders

Top 5 by Value

Rubric Capital Management LP

BlackRock, Inc.

State Street CORP

D. E. Shaw & Co., Inc.

Top 5 by Conviction

Rangeley Capital, LLC

Birchview Capital, LP

Penbrook Management LLC

Palo Alto Investors LP

Monimus Capital Management, LP

View all 186 holding institutions

Quarterly Activity

Recent Activity

+$254.0M

Total Buy Value

$164.0M

Total Sell Value

New buy24

Trim53

Add67

Sold out23

91

Net Buyers

76

Net Sellers

Insider Trading (Form 4)

Form 144 Pre-Sale Notices

1

Filings (90d)

$740K

Total Est. Value

80K shares

Planned Shares

Last Filed 2026-06-09

Filer	Title/Relationship	Filing Date	Planned Shares	Est. Value
Malecek Michael J	Previous Officer	2026-06-09	80K shares	$740K

Form 144 is a planned sale notice, not an executed transaction. Form 144 Tracker。

Beneficial Ownership (13D/13G)

No Schedule 13D/13G filings for this ticker

Material Events (8-K)

No Form 8-K filings for this ticker

FAQ

Who are the top institutional investors holding Prothena Corporation plc (PRTA)?

Major stakeholders currently include FMR LLC ($73.4M), Rubric Capital Management LP ($48.6M), BlackRock, Inc. ($45.1M). Based on the latest 13F filings, there are a total of 186 tracked investment funds and institutions maintaining positions in PRTA.

What is the overall institutional sentiment toward PRTA recently?

Institutional sentiment appears Bearish (Net Selling). During the most recent reporting quarter, the stock experienced a net outflow of $2.4M, driven by 91 managers accumulating shares while 76 reduced their exposure.

Which institutions have been selling or reducing their PRTA positions?

In the latest period, 53 funds trimmed their holdings, and 23 managers completely exited their positions. The aggregate reported sell value was $164.0M.

Are there any notable investors adding PRTA to their portfolios?

Yes, buying activity remains notable. 24 institutions opened new positions in {ticker}, and 67 existing holders added to their shares. The total reported buy value for the quarter amounted to $254.0M.

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