PRTA
Prothena Corp Public Ltd Co
Prothena Corp Public Ltd Co insider trading
Insiders at Prothena Corp Public Ltd Co have been buying its stock on the open market. The largest purchase in the last 30 days was Scully William P (10% Owner) buying $843.5K of PRTA, filed Sep 21, 2026. Every open-market purchase and sale its officers, directors and 10% owners filed in that time is listed below, each linked to the original Form 4.
- Bought on the open market
- $843.5K
- Sold
- —
- Insiders
- 1
- Latest trade
- Sep 18, 2026
From SEC filings · last 30 days
Recent PRTA insider transactions
Scully William P10% Owner
Bought 100,000 sh at $8.43 · Sep 18, 2026
$843.5K
Filing
SEC Form 4 data, Q3 2024 to Q2 2026
PRTA insider trading by quarter
Between Jul 01, 2024 and Jun 30, 2026, 2 insiders traded PRTA on the open market: 11 purchases worth $5.8M and 3 sales worth $50.8M. In the last four quarters alone: 5 purchases ($3.1M) and 0 sales, by one insider.
| Quarter | Bought | Sold | Insiders |
|---|---|---|---|
| Q2 2026 | +$3.1M5 buys | — | |
| Q1 2026 | — | — | |
| Q4 2025 | — | — | |
| Q3 2025 | — | — | |
| Q2 2025 | — | −$50.8M3 sales | |
| Q1 2025 | +$1.3M1 buy | — | |
| Q4 2024 | +$1.5M5 buys | — | |
| Q3 2024 | — | — |
- Largest purchase
- +$1.3M of PRTA by Scully William P (10% Owner) on Jan 14, 2025.
- Largest sale
- −$27.7M of PRTA by EcoR1 Capital, LLC (10% Owner) on May 02, 2025.
Open-market transactions through Jun 30, 2026most recent first
Scully William P
10% Owner
+$158K
Jun 16, 2026
20,000 sh · $7.90
Scully William P
10% Owner
+$1M
Jun 11, 2026
125,000 sh · $8.17
Scully William P
10% Owner
+$465.5K
Jun 04, 2026
50,000 sh · $9.31
Scully William P
10% Owner
+$471.5K
Jun 02, 2026
50,000 sh · $9.43
Scully William P
10% Owner
+$981K
May 22, 2026
100,000 sh · $9.81
EcoR1 Capital, LLC
10% Owner
−$15.2M
May 06, 2025
1,984,053 sh · $7.64
EcoR1 Capital, LLC
10% Owner
−$7.9M
May 05, 2025
977,693 sh · $8.11
EcoR1 Capital, LLC
10% Owner
−$27.7M
May 02, 2025
3,317,938 sh · $8.36
Scully William P
10% Owner
+$1.3M
Jan 14, 2025
100,000 sh · $12.79
Scully William P
10% Owner
+$389.7K
Dec 31, 2024
30,000 sh · $12.99
Scully William P
10% Owner
+$16K
Dec 31, 2024
1,200 sh · $13.37
Scully William P
10% Owner
+$10.7K
Dec 31, 2024
800 sh · $13.39
Scully William P
10% Owner
+$31.8K
Dec 20, 2024
2,000 sh · $15.91
Scully William P
10% Owner
+$1M
Dec 18, 2024
73,436 sh · $13.93
| Date | Insider | Shares | Price | Value |
|---|---|---|---|---|
| Jun 16, 2026 | Scully William P10% Owner | 20,000 | $7.90 | +$158K |
| Jun 11, 2026 | Scully William P10% Owner | 125,000 | $8.17 | +$1M |
| Jun 04, 2026 | Scully William P10% Owner | 50,000 | $9.31 | +$465.5K |
| Jun 02, 2026 | Scully William P10% Owner | 50,000 | $9.43 | +$471.5K |
| May 22, 2026 | Scully William P10% Owner | 100,000 | $9.81 | +$981K |
| May 06, 2025 | EcoR1 Capital, LLC10% Owner | 1,984,053 | $7.64 | −$15.2M |
| May 05, 2025 | EcoR1 Capital, LLC10% Owner | 977,693 | $8.11 | −$7.9M |
| May 02, 2025 | EcoR1 Capital, LLC10% Owner | 3,317,938 | $8.36 | −$27.7M |
| Jan 14, 2025 | Scully William P10% Owner | 100,000 | $12.79 | +$1.3M |
| Dec 31, 2024 | Scully William P10% Owner | 30,000 | $12.99 | +$389.7K |
| Dec 31, 2024 | Scully William P10% Owner | 1,200 | $13.37 | +$16K |
| Dec 31, 2024 | Scully William P10% Owner | 800 | $13.39 | +$10.7K |
| Dec 20, 2024 | Scully William P10% Owner | 2,000 | $15.91 | +$31.8K |
| Dec 18, 2024 | Scully William P10% Owner | 73,436 | $13.93 | +$1M |
From SEC's quarterly Form 3, 4 and 5 data sets: code P purchases and code S sales of common stock, by the date the trade happened. Where a fund and the people who control it each report the same block, it is counted once. Trades made in the last days of Q2 2026 but filed after it closed arrive with SEC's next quarterly release.
Don't check PRTA — let it ping you
Watch every insider filing the minute it clears the SEC
The live dashboard reads every Form 4 as it lands and puts it in plain English — open-market buys, cluster buys where several insiders move at once, and the sales executives chose to make rather than scheduled. Free to open; Pro adds alerts, watchlists and each buyer's track record.
Prothena Corp Public Ltd Co is outside the 777 companies InsiderPulse scans continuously. This page is built from the filings on the live tape and stays up while its insiders are buying. Monitoring, not advice.
Other companies insiders are buying now
Questions
- Are PRTA insiders buying or selling?
- Between Sep 18, 2026 and Sep 18, 2026, 1 Prothena Corp Public Ltd Co insider made 1 open-market purchase worth $843.5K and no sales, a net purchase of $843.5K.
- How much PRTA stock have insiders bought and sold in the last two years?
- Between Jul 01, 2024 and Jun 30, 2026, 2 Prothena Corp Public Ltd Co insiders made 11 open-market purchases worth $5.8M and 3 sales worth $50.8M. In the four quarters to Jun 30, 2026: 5 purchases ($3.1M) and no sales. The largest purchase was Scully William P buying $1.3M on Jan 14, 2025. The largest sale was EcoR1 Capital, LLC selling $27.7M on May 02, 2025.
- What was the largest recent PRTA insider trade?
- Scully William P (10% Owner) bought $843.5K of PRTA stock on Sep 18, 2026 at about $8.43 a share.
- When did an insider last buy PRTA shares?
- The most recent open-market purchase on file is Scully William P (10% Owner) buying $843.5K on Sep 18, 2026.
- Where does PRTA insider trading data come from?
- From the Form 4 filings Prothena Corp Public Ltd Co's officers, directors and 10% owners must send the SEC within two business days of a trade. Each row on this page links to its original filing on SEC EDGAR. Share grants and option exercises are kept apart from open-market purchases and sales, because only the latter cost the insider their own money.
Get the free Insider Brief
Each weekday evening: the day's biggest open-market insider buys, cluster formations and 10b5-1 plan breaks — in plain English, with grants and routine vesting stripped out. Honest about what the data can and cannot say.