PRTA

Prothena Corp PLC$8.47 0.47%
Health CareUSCUSIP G72800108· EOD Jul 16, 2026◍ Confluence graph
Tracked 13F Holders
153
+5 QoQ
13F Value (tracked)
$429.5M
Insider Net · 180d
$3.1M
1↑ 0↓
Recent Filings
15
Smart-money sentimentBullish
BearishBullish
13F funds (latest Q)34 adding · 16 trimming
Insider net (180d)+$3.1M

Price & smart-money activity

$8.47 0.47%5Y -82.9%
$4.23$24.30$44.37$64.44$84.51202120222023202420252026224362033635
Hover for who · click for detailEnd-of-day closing prices52w $6.26 – $11.51
Build

Ask your agent what changed in PRTA

This stock page is the public Follow view. For one current, evidence-backed answer, use capital_change_brief through REST or MCP. It compares tracked 13F changes with qualifying Form 4 activity and cites the SEC evidence.

Copy-paste
curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://arkolith.com/api/v1/stocks/PRTA/capital-change-brief"
Ask your agent
Use Arkolith's capital_change_brief for PRTA.
Tell me what changed, whether insider activity
corroborates it, and cite the SEC evidence.

Top institutional holders

153 tracked 13F filers
#FundPosition valueSharesLast moveAs ofHistory
1FMR LLC
$73.4M
7.6M
Held
Q1 2026
2Rubric Capital Management LP
$48.6M
5.0M
+36%
Added · +1.3M sh
Q1 2026
3BlackRock, Inc.
$45.1M
4.6M
+13%
Added · +537K sh
Q1 2026
4STATE STREET CORP
$18.8M
1.9M
−15%
Reduced · −329K sh
Q1 2026
5D. E. Shaw & Co., Inc.
$17.1M
1.8M
+4.9%
Added · +82K sh
Q1 2026
6ADAR1 Capital Management, LLC
$15.4M
1.6M
+8.5%
Added · +124K sh
Q1 2026
7VANGUARD PORTFOLIO MANAGEMENT LLC
$14.1M
1.4M
New
+1.4M sh
Q1 2026
8MORGAN STANLEY
$12.0M
1.2M
−1.3%
Reduced · −16K sh
Q1 2026
9Palo Alto Investors LP
$11.7M
1.2M
−8.5%
Reduced · −112K sh
Q1 2026
10TWO SIGMA INVESTMENTS, LP
$11.7M
1.2M
+80%
Added · +536K sh
Q1 2026
11GEODE CAPITAL MANAGEMENT, LLC
$10.7M
1.1M
+3.3%
Added · +35K sh
Q1 2026
12FEDERATED HERMES, INC.
$10.3M
1.1M
+8.8%
Added · +85K sh
Q1 2026
13JACOBS LEVY EQUITY MANAGEMENT, INC
$9.4M
972K
−0.6%
Reduced · −6K sh
Q1 2026
14GOLDMAN SACHS GROUP INC
$8.0M
819K
−12%
Reduced · −116K sh
Q1 2026
15DIMENSIONAL FUND ADVISORS LP
$7.6M
783K
+0.9%
Added · +7K sh
Q1 2026
16Nuveen, LLC
$7.4M
759K
~0%
Added · +261 sh
Q1 2026
17Qube Research & Technologies Ltd
$6.0M
615K
+51%
Added · +207K sh
Q1 2026
18RENAISSANCE TECHNOLOGIES LLC
$5.9M
608K
+39%
Added · +172K sh
Q1 2026
19Mariner, LLC
$5.5M
563K
−2.6%
Reduced · −15K sh
Q1 2026
20MONIMUS CAPITAL MANAGEMENT, LP
$4.7M
486K
+91%
Added · +231K sh
Q1 2026
21VANGUARD CAPITAL MANAGEMENT LLC
$4.7M
484K
New
+484K sh
Q1 2026
22Rangeley Capital, LLC
$4.4M
449K
−14%
Reduced · −75K sh
Q1 2026
23Birchview Capital, LP
$4.4M
449K
+1.8%
Added · +8K sh
Q1 2026
24ARMISTICE CAPITAL, LLC
$4.3M
439K
−71%
Reduced · −1.1M sh
Q1 2026
25CITADEL ADVISORS LLC
$4.2M
436K
−52%
Reduced · −477K sh
Q1 2026

Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership.

Fund activity: latest quarter

Opened (NEW)
5
funds
Added
29
funds
Reduced
16
funds
Exited
0
funds

Insider activity (Form 4)

Full insider page →
Buys · 180d
$3.1M
1 insiders
Sells · 180d
$0
0 insiders
Net
$3.1M
5 P/S txns
Signal
Net Buying
open-market
DateInsiderRoleActionSharesValue
Jun 16, 2026SCULLY WILLIAM P10% OwnerBuy (P)20K$158K
Jun 15, 2026SCULLY WILLIAM P10% OwnerGift (G)325K$0
Jun 11, 2026SCULLY WILLIAM P10% OwnerBuy (P)125K$1.0M
Jun 4, 2026SCULLY WILLIAM P10% OwnerBuy (P)50K$465K
Jun 2, 2026SCULLY WILLIAM P10% OwnerBuy (P)50K$471K
May 22, 2026SCULLY WILLIAM P10% OwnerBuy (P)100K$981K
May 15, 2026Ekman LarsDirectorGrant (A)27K$0
May 15, 2026COLLIER RICHARD TDirectorGrant (A)27K$0
May 15, 2026Cooke ShaneDirectorGrant (A)27K$0
May 15, 2026Dunn William H. Jr.DirectorGrant (A)27K$0
May 15, 2026Selkoe Dennis J.DirectorGrant (A)27K$0
May 15, 2026WELCH DANIEL GDirectorGrant (A)27K$0

Institutional ownership over time

153 funds+40 since Q3 2024
077153Q3 2024Q1 2025Q3 2025Q1 2026
funds holding aggregate valuelatest $430.4M

Funds that own PRTA also own

CompanyCo-held byCombined value
MICROSOFT CORPMSFT57 funds$24.7B
BROADCOM INCAVGO57 funds$14.4B
AMAZON.COM INCAMZN56 funds$19.1B
META PLATFORMS INC-CLASS AMETA56 funds$11.5B
ELI LILLY & COLLY56 funds$6.0B
VISA INC-CLASS A SHARESV56 funds$4.6B
COSTCO WHOLESALE CORPCOST56 funds$4.4B
MICRON TECHNOLOGY INCMU55 funds$6.8B
PALANTIR TECHNOLOGIES INC-APLTR55 funds$3.6B
UNITEDHEALTH GROUP INCUNH55 funds$2.8B
CITIGROUP INCC55 funds$2.4B
BOSTON SCIENTIFIC CORPBSX55 funds$2.2B

Ranked by how many of PRTA's institutional holders also hold each name, a cross-fund conviction signal. Via the MCP server (ticker.co_held).

Recent filings

15 shown

Browse more

13F holdings + Form 4 insider transactions + end-of-day price history + the live filing stream, joined for PRTA. Filings are public domain, sourced to SEC EDGAR; price series derived from end-of-day closes. Every panel above is one call to the Arkolith API & MCP server.