What is an open-market purchase (Form 4 code P)?

An open-market purchase is exactly what it sounds like: a corporate insider places an order through a broker and buys their company's shares on the exchange, at the market price, with their own money. On the Form 4 it appears as transaction code P in Table I.

What it is not

• Not a grant (code A) — that's the company giving shares as pay.
• Not an option exercise (code M) — that's converting compensation already awarded.
• Not tax withholding (code F) or a gift (code G).
• Sometimes not even a market trade — code P also covers private purchases; the footnotes say which.

The full list is in Form 4 transaction codes explained.

Reading size and context

Signal scales with commitment. A $5,000 optics buy after an ugly earnings call is noise; a purchase that's large relative to the insider's salary and existing stake is information. We surface every open-market buy so you can weigh size in context, weight C-suite buyers over passive holders, and — most importantly — watch for multiple insiders buying within the same rolling window. Every qualifying purchase we've parsed is browsable per stock on the stocks directory and per person on the insider leaderboard.