SEC Filings
What is Form 4 (Insider Transactions)?
The filing officers, directors and 10% owners must make within two business days of trading their company's stock.
Form 4 shows who traded, how many shares, at what price and what they own afterwards. Transaction code P is an open-market purchase, S a sale, A an award, M an option exercise and F shares withheld for tax. Open-market purchases are the most informative — insiders sell for many reasons, but they buy for one.