PRTA insiders were on both sides of the trade this year. Buys came to roughly $9.9 million (one buyer), sales to $136,000 (two sellers).
Biggest single buyer: SCULLY WILLIAM P, 10% Owner, with roughly $1.4 million.
Quarter by quarter: 2 quarters in a row of net buying by insiders. Insiders bought in 3 of the last 7 full quarters. Big money check: 188 institutions held PRTA as of Q2 2026, and funds were split between buying and selling.
| Filed | Insider | Role | Type | Shares | Price | Value | Source |
|---|---|---|---|---|---|---|---|
| Oct 9, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 125,000 | $8.40 | $1.1M | SEC |
| Oct 9, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 90,000 | $8.57 | $771K | SEC |
| Oct 6, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 100,000 | $8.57 | $857K | SEC |
| Sep 30, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 162,000 | $8.68 | $1.4M | SEC |
| Sep 29, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 103,500 | $8.60 | $890K | SEC |
| Sep 21, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 100,000 | $8.43 | $843K | SEC |
| Sep 3, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 27,000 | $9.47 | $256K | SEC |
| Aug 21, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 50,000 | $8.79 | $440K | SEC |
| Aug 10, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 3,500 | $8.62 | $30K | SEC |
| Aug 10, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 34,000 | $8.62 | $293K | SEC |
| Jul 30, 2026 | Kingston Anne Evans | Executive Officer | Sell | 7,662 | $8.47 | $65K | SEC |
| Jul 30, 2026 | Isaacs Michael John | Executive Officer | Sell | 8,386 | $8.47 | $71K | SEC |
| Jun 18, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 20,000 | $7.90 | $158K | SEC |
| Jun 12, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 125,000 | $8.17 | $1.0M | SEC |
| Jun 5, 2026 | SCULLY WILLIAM P | 10% Owner | Buy | 50,000 | $9.31 | $466K | SEC |
In the last 12 months Prothena Corp Public Ltd Co insiders made open-market purchases worth about $9.9 million and sales worth about $136,000. Data comes from SEC Form 4 filings, updated every 30 minutes on CapitalSnitch.
The most recent open-market insider trade in PRTA was filed on 2026-10-09.
188 investment managers reported holding PRTA in SEC Form 13F filings for Q2 2026.
No congressional trades in PRTA were reported in the past two years. The full list is free on CapitalSnitch.
Public-record data for research and education, not investment advice. Insider sales are often pre-planned (10b5-1). Congress data: Data derived from public disclosures filed under the Ethics in Government Act and the STOCK Act, republished free for public transparency and news reporting. Disclosures may lag the trade by 45 days or more and show amounts only as ranges. This data may not be used for credit rating, loan underwriting, solicitation of money (political, charitable or other), direct-mail or commercial targeting (5 U.S.C. 13107).