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PRTA
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Prothena Corporation plc

PRTA · Healthcare · Prothena Corporation plc, a late-stage clinical biotechnology company, focuses on discovery and development of novel therapies to treat dis…

Prothena Corporation plc (PRTA), in the Healthcare sector, has 15 disclosed filings on Paydirt over the trailing twelve months from 1 corporate insider: 15 purchases and 0 sales. Filers took a median of 2 days from execution to disclosure, and the most recent trade was executed Oct 23 and filed Oct 26. The most active filer was William P Scully with 15 filings. Data as of Nov 8 2026.

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Filings, ttm
15
15 buys · 0 sells
Traders, ttm
1
1 insider
Volume, ttmiDollar value disclosed in the window
$12.0M
estimated for Congress, as filed for insiders
Median delay
2d
execution to disclosure
Last traded
Oct 23
Filed Oct 26
ADViAverage daily dollar volume
$4.9M
market data
Share price · 12M
$8.47 (-19.6%)
$11.51$9.71$7.91Nov 10 2025May 7Oct 30

Adjusted for splits and dividends.

Volume by month
$50.8M$25.4M$0Dec 2024Jun 2025Dec 2025Jun 2026May 2025 · buys $2.7MMay 2025 · sells $50.8MMay 2026 · buys $981KJun 2026 · buys $2.1MAug 2026 · buys $732KSep 2026 · buys $3.4MOct 2026 · buys $4.7M
Buys $14.7M Sells $50.8M

Estimated for Congress, as filed for insiders · by filing month · past 24 months

Who filed · past 24 months
WS William P Scully 10% owner 16 filings · 16 buys, 0 sales EL EcoR1 Capital, LLC Director 1 filing · 0 buys, 1 sale
Recent filings
William P ScullyPURCHASE 10% owner $1.2M
150,000 sh across 2 lots
Exec Oct 22
Filed Oct 26 · 4:20 PM ET William P ScullyPURCHASE 10% owner $835K
100,000 sh × $8.35
Exec Oct 13
Filed Oct 15 · 4:21 PM ET William P ScullyPURCHASE 10% owner $1.8M
215,000 sh across 2 lots
Exec Oct 7
Filed Oct 9 · 9:43 AM ET William P ScullyPURCHASE 10% owner $857K
100,000 sh × $8.57
Exec Oct 2
Filed Oct 6 · 1:53 PM ET William P ScullyPURCHASE 10% owner $1.4M
162,000 sh × $8.68
Exec Sep 29
Filed Sep 30 · 5:10 PM ET William P ScullyPURCHASE 10% owner $890K
103,500 sh × $8.60
Exec Sep 28
Filed Sep 29 · 5:37 PM ET William P ScullyPURCHASE 10% owner $843K
100,000 sh × $8.43
Exec Sep 18
Filed Sep 21 · 4:23 PM ET William P ScullyPURCHASE 10% owner $256K
27,000 sh × $9.47
Exec Sep 2
Filed Sep 3 · 6:23 PM ET William P ScullyPURCHASE 10% owner $439K
50,000 sh × $8.79
Exec Aug 20
Filed Aug 21 · 2:32 PM ET William P ScullyPURCHASE 10% owner $293K
34,000 sh × $8.62
Exec Aug 7
Filed Aug 10 · 3:24 PM ET William P ScullyPURCHASE 10% owner $158K
20,000 sh × $7.90
Exec Jun 16
Filed Jun 18 · 11:38 AM ET William P ScullyPURCHASE 10% owner $1.0M
125,000 sh × $8.17
Exec Jun 11
Filed Jun 12 · 5:59 PM ET William P ScullyPURCHASE 10% owner $465K
50,000 sh × $9.31
Exec Jun 4
Filed Jun 5 · 1:46 PM ET William P ScullyPURCHASE 10% owner $471K
50,000 sh × $9.43
Exec Jun 2
Filed Jun 3 · 12:41 PM ET William P ScullyPURCHASE 10% owner $981K
100,000 sh × $9.81
Exec May 22
Filed May 26 · 2:51 PM ET EcoR1 Capital, LLCSALE 10% owner $50.8M
6,279,684 sh across 3 lots
Exec May 2 2025
Filed May 6 2025 · 5:30 PM ET William P ScullyPURCHASE 10% owner $2.7M
203,436 sh across 3 lots
Exec Dec 18 2024
Filed May 2 2025 · 5:30 PM ET †