About this page
Insider trades reported on SEC Form 4: when the people who run a company buy or sell its shares with their own money.
How to read it
- Form 4
- The form a company insider (officer, director or owner of more than 10%) must file with the SEC within two business days of buying or selling the company's shares.
- Buy (P) and Sell (S)
- Open-market purchases and sales. Gifts, option exercises and automatic tax withholding are left out because they say little about what the insider thinks.
- Value
- Shares times price, as reported on the filing.
- 10b5-1
- A trade made under a plan set up in advance. Planned sales are common and usually say less than an unplanned purchase.
- Late filing
- A Form 4 filed more than two business days after the trade.
- Vs. S&P 500
- How the stock did after the trade minus how the overall market did in the same weeks.
A real example
In January 2016, when bank stocks were falling, JPMorgan Chase CEO Jamie Dimon bought 500,000 JPMorgan shares with his own money, worth about $26 million. His Form 4 made the purchase public within days, and investors read it as a strong sign of confidence.
Explain it like I'm 13
If the coach of a team bets his own allowance that his team will win, that tells you something. A Form 4 is the note a company boss must hand in whenever he buys or sells his own company's shares, so everyone can see it.
Data from public SEC filings and congressional reports. Information, not investment advice. Check every number against the filing linked on the page.
PROTHENA CORP PUBLIC LTD CO (PRTA): Insider Trades and Fund Holdings
In the past 12 months, PROTHENA CORP PUBLIC LTD CO insiders reported 15 open-market purchases worth $9.14M and 2 sales worth $136K; 2 of the sales were reported as made under a 10b5-1 trading plan.
Timeline: news and trades
Company filings (8-K), insider trades, notices of planned sales (Form 144), Congress trades and fund moves in the past year, newest first.
- Oct 23, 2026Insider buy10% owner William P. Scully bought $403,525
- Oct 22, 2026Insider buy10% owner William P. Scully bought $818,520
- Oct 14, 2026Insider buy10% owner William P. Scully bought $84,569
- Oct 13, 2026Insider buy10% owner William P. Scully bought $835,480
- Oct 8, 2026Insider buy10% owner William P. Scully bought $770,904 (6 days after: executive or director change)
- Oct 7, 2026Insider buy10% owner William P. Scully bought $1.1 million (5 days after: executive or director change)
- Oct 2, 2026NewsCompany reported: Executive or director change
- Oct 2, 2026Insider buy10% owner William P. Scully bought $857,240 (0 days after: executive or director change)
- Sep 29, 2026Insider buy10% owner William P. Scully bought $1.4 million
- Sep 28, 2026Insider buy10% owner William P. Scully bought $889,872
- Sep 18, 2026Insider buy10% owner William P. Scully bought $843,460
- Sep 2, 2026Insider buy10% owner William P. Scully bought $255,739
- Aug 20, 2026Insider buy10% owner William P. Scully bought $439,430
- Aug 7, 2026Insider buy10% owner William P. Scully bought $323,220 (1 days after: quarterly or annual results)
- Aug 6, 2026NewsCompany reported: Quarterly or annual results
- Jul 29, 2026Insider saleGeneral Counsel Michael John Isaacs sold $71,055 under a 10b5-1 plan
- Jul 29, 2026Insider saleChief Strategy Officer Anne Evans Kingston sold $64,919 under a 10b5-1 plan
- Jul 29, 2026Planned saleMICHAEL JOHN ISAACS (officer) filed notice to sell about $71,055 around Jul 29, 2026
- Jul 29, 2026Planned saleANNE KINGSTON (officer) filed notice to sell about $64,919 around Jul 29, 2026
- Jun 30, 2026FundRenaissance Technologies added 15% in Q2 2026 (13F filed Aug 13, 2026)
- Jun 16, 2026Insider buy10% owner William P. Scully bought $157,990
Recent insider trades
Open-market purchases (code P) and sales (code S) from Form 4. Grants, option exercises and gifts are not shown. Latest filing: Oct 26, 2026.
| Filed | Insider | Type | Value | Score |
|---|---|---|---|---|
| Oct 26 | William P. Scully10% owner | ▲ BUY | $819K | 23 |
| Oct 26 | William P. Scully10% owner | ▲ BUY | $404K | 15 |
| Oct 15 | William P. Scully10% owner | ▲ BUY | $835K | 27 |
| Oct 15 | William P. Scully10% owner | ▲ BUY | $85K | 10 |
| Oct 9 | William P. Scully10% owner | ▲ BUY | $1.05M | 35 |
| Oct 9 | William P. Scully10% owner | ▲ BUY | $771K | 32 |
| Oct 6 | William P. Scully10% owner | ▲ BUY | $857K | 39 |
| Sep 30 | William P. Scully10% owner | ▲ BUY | $1.41M | 47 |
| Sep 29 | William P. Scully10% owner | ▲ BUY | $890K | 44 |
| Sep 21 | William P. Scully10% owner | ▲ BUY | $843K | 27 |
Insiders who traded in the past year
| Insider | Role | Buys | Bought | Sells | Sold |
|---|---|---|---|---|---|
| William P. Scully | 10% owner | 15 | $9.14M | 0 | $0 |
| Michael John Isaacs | General Counsel | 0 | $0 | 1 | $71K |
| Anne Evans Kingston | Chief Strategy Officer | 0 | $0 | 1 | $65K |
47 William P. Scully (10% owner), 2026-09-29. What the score means
A All 17 insider trades reported on time. How it is graded
Tracked funds that report PRTA
From each fund's latest 13F. Holdings are as of quarter end and are filed up to 45 days later.
| Fund | Shares | Value | Change |
|---|---|---|---|
| Renaissance Technologies | 697,615 | $6.83M | ▲ +14.8% |
Reading these numbers
Insiders sell for many reasons: taxes, diversification, a house. Purchases with their own money are rarer and are usually read as more informative. A Form 4 is due within two business days of the trade. How to read a Form 4 →