Nasdaq logged its worst week since June, closing Friday, October 16 as investors rotated out of AI stocks and oil prices rose (Schaeffer's Research). Insiders who traded that week have two business days to report it, so the filings are arriving now. Most of the headlines about them will read the numbers wrong.
What is a Form 4 filing?
A Form 4 is the report that company officers, directors, and owners of more than 10% of a company's stock file when their holdings change. It is due within two business days of the trade, and it goes straight into EDGAR, the SEC's public database (SEC guide to Forms 3, 4, and 5).
Which Form 4 trades carry the most information?
Open-market purchases, coded P on the form, are the cleanest signal. An insider who buys shares on the open market is spending their own cash at whatever price the market set that day. Open-market sales, coded S, are much noisier. Executives sell to diversify, to cover taxes, to buy a home, or because a sale was scheduled months earlier under a Rule 10b5-1 trading plan. A sale tells you someone wanted less exposure to one company. It rarely tells you why.
Why do big insider sales so often mislead?
A single Form 4 can hold several kinds of transactions, and the dollar total in a headline is not always a market sale. Option exercises and tax withholdings are reported on the same form. An executive who exercises options and sells the shares will show both. Check the transaction type before the dollar figure. A $20 million total that is mostly tax withholding says something very different from a $20 million open-market sale.
Does a sell-off change how to read insider buying?
Insider buying during a sell-off is easier to notice, because fewer investors are buying into weakness. A single purchase is one data point. A cluster matters more: several insiders at the same company buying within a short window, with meaningful amounts of their own money. Even then, the filing shows what the insider did, not what they expect next. A purchase is a decision, not a forecast.
How do you track Form 4 filings on OpticAlpha?
The Research & Filings section of the terminal pulls Form 4 filings directly from SEC EDGAR. It shows open-market purchases and sales with a $100,000 minimum over a 30-day rolling window. You can filter by type, minimum value, and ticker, and search by insider name or title. The insider trades feature page explains each field.
Track live insider filings at opticalpha.net/terminal. 14-day free trial, no credit card required.