Skip to content
Insider tapeFilings through Fri, Oct 9
Watchlist
PRTA

PROTHENA CORP PUBLIC LTD (PRTA) stock: insider trades, news & valuation

Health Care · Net buying
Close · Oct 9, 2026 $8.84 +2.7% on the day -14.2% over 12 months 52-week range $7.91 – $11.51

Share price and insider trades

PRTA closeInsider buyInsider sale
681012NovDecJan 2026FebMarAprMayJunJulAugSepOctSold $135,927 on 2026-07-29 · Anne Evans Kingston, Michael John IsaacsBought $158,000 on 2026-06-16 · William P ScullyBought $255,690 on 2026-09-02 · William P ScullyBought $323,250 on 2026-08-07 · William P ScullyBought $439,500 on 2026-08-20 · William P ScullyBought $465,500 on 2026-06-04 · William P ScullyBought $471,500 on 2026-06-02 · William P ScullyBought $770,904 on 2026-10-08 · William P ScullyBought $843,000 on 2026-09-18 · William P ScullyBought $857,240 on 2026-10-02 · William P ScullyBought $890,100 on 2026-09-28 · William P ScullyBought $981,000 on 2026-05-22 · William P ScullyBought $1,021,250 on 2026-06-11 · William P ScullyBought $1,050,150 on 2026-10-07 · William P ScullyBought $1,406,160 on 2026-09-29 · William P Scully
Bought, 12 months$9.9M
Sold, 12 months$136K
Insiders buying1
Insiders selling2

PROTHENA CORP PUBLIC LTD insider trading at a glance (Oct 9, 2026): in the past 12 months, 1 insider bought $9.9M and 2 sold $136K of PRTA stock on the open market.

PRTA insider buying and selling by quarter

Open-market purchases (green, above the line) and sales (red, below), by trade date.

Q2 2026: $3.1M bought (5 trades)$3.1MQ2 2026Q3 2026: $4.2M bought (7 trades)$4.2MQ3 2026: $136K sold (2 trades)Q3 2026Q4 2026: $2.7M bought (3 trades)$2.7MQ4 2026
QuarterBoughtPurchasesSoldSales
Q4 2026$2.7M3—0
Q3 2026$4.2M7$136K2
Q2 2026$3.1M5—0

Valuation, profit and volume

Pick score 46/100
P/E (trailing)n/aSector median 24.7
Market value$454MBiotechnology
Profit margin-80.7%Revenue growth -77.1%
Volume vs. 50-day1.5×Last 5 sessions
Insiders' paper profit+$144KOn all tracked purchases +1.5%

Summary

Over the past 12 months, 1 PROTHENA CORP PUBLIC LTD CO insider reported open-market purchases totaling $9.9M, while 2 insiders reported sales totaling $136K. Among insiders with enough purchase history to measure, William P Scully (10% Owner) has the highest Insider Score at 50. 2 of 2 recorded sales were made under pre-scheduled Rule 10b5-1 trading plans, which are usually less informative than discretionary sales.

PRTA stock news and SEC filings

Recent 8-K filings and headlines. Tone is scored from the headline wording; “Policy” marks regulatory, trade or government topics.

Insider transactions

Open-market purchases and sales.

Filed Insider Type Shares Price Value Since Score
Oct 9 NewSEC William P Scully10% Owner Buy 125,000439,000 held (+40%) $8.40 $1.1M +5.2% 50
Oct 9 NewSEC William P Scully10% Owner Buy 90,000529,000 held (+21%) $8.57 $771K +3.2% 50
Oct 6SEC William P Scully10% Owner Buy 100,000314,000 held (+47%) $8.57 $857K +3.1% 50
Sep 30SEC William P Scully10% Owner Buy 162,000214,000 held (+312%) $8.68 $1.4M +1.8% 50
Sep 29SEC William P Scully10% Owner Buy 103,500187,000 held (+124%) $8.60 $890K +2.8% 50
Sep 21SEC William P Scully10% Owner Buy 100,000927,000 held (+12%) $8.43 $843K +4.9% 50
Sep 3SEC William P Scully10% Owner Buy 27,000827,000 held (+3%) $9.47 $256K -6.7% 50
Aug 21SEC William P Scully10% Owner Buy 50,000800,000 held (+7%) $8.79 $440K +0.6% 50
Aug 10SEC William P Scully10% Owner Buy 34,000790,000 held (+4%) $8.62 $293K +2.6% 50
Aug 10SEC William P Scully10% Owner Buy 3,50083,500 held (+4%) $8.62 $30K +2.6% 50
Jul 30SEC Michael John IsaacsGeneral Counsel Sell Plan 8,38635,745 held (−19%) $8.47 $71K +4.4% —
Jul 30SEC Anne Evans KingstonChief Strategy Officer Sell Plan 7,66255,782 held (−12%) $8.47 $65K +4.4% —
Jun 18SEC William P Scully10% Owner Buy 20,000756,000 held (+3%) $7.90 $158K +11.9% 50
Jun 12SEC William P Scully10% Owner Buy 125,0001,061,000 held (+13%) $8.17 $1.0M +8.2% 50
Jun 5SEC William P Scully10% Owner Buy 50,000936,000 held (+6%) $9.31 $466K -5.0% 50
Jun 3SEC William P Scully10% Owner Buy 50,000886,000 held (+6%) $9.43 $472K -6.3% 50
May 26SEC William P Scully10% Owner Buy 100,000836,000 held (+14%) $9.81 $981K -9.9% 50

Insiders at PROTHENA CORP PUBLIC LTD CO

InsiderBoughtSoldLast filingScore
William P Scully10% Owner $9.9M — Oct 9, 2026 50
Michael John IsaacsGeneral Counsel — $71K Jul 30, 2026 —
Anne Evans KingstonChief Strategy Officer — $65K Jul 30, 2026 —

Insider activity at other Health Care companies

Same sector, ranked by insider buying in the last 90 days.

  • SLBTSL Science Holding Ltd$10329.90B bought
  • KODKodiak Sciences Inc.$157M bought
  • ADRXADARx Pharmaceuticals, Inc.$87.7M bought
  • ATTOAttovia Therapeutics, Inc.$72.9M bought
  • MPLTMapLight Therapeutics, Inc.$65.5M bought
  • AVRAnteris Technologies Global Corp.$40.4M bought

PRTA stock: common questions

Are PROTHENA CORP PUBLIC LTD CO insiders buying PRTA stock?

In the past 12 months, 1 insiders reported open-market purchases of PRTA worth $9.9M. The latest was 10% Owner William P Scully bought $1.1M of PRTA at $8.40 — raises the stake by 40%.

Are PROTHENA CORP PUBLIC LTD CO insiders selling PRTA stock?

2 insiders reported sales worth $136K over the same period.

Where does this data come from?

Every transaction comes from Form 4 filings that insiders must submit to the SEC within two business days of a trade. We pull them from SEC EDGAR every night.

What is PRTA's 52-week range?

Over the past year PRTA has traded between $7.91 and $11.51. It last closed at $8.84 on Oct 9, 2026.