Form 4 transaction codes: open-market buys vs grants, exercises and sales
Every transaction on a Form 4 carries a one-letter code saying what kind of trade it was. Most Form 4s aren't insiders choosing to buy or sell: they're awards, option exercises and shares withheld for taxes. Reading the code, and the footnotes, is how you separate real buying from paperwork.
The common codes
| Code | What it means | Is it an open-market buy? |
|---|---|---|
| P | Purchase on an exchange or from another person | Usually, but check the footnotes: it can be a private placement or an offering |
| S | Sale on an exchange or to another person | No, it's a sale |
| A | Grant or award from the company | No: given, not bought |
| M | Exercise or conversion of a derivative, such as an option | No: the price was set in advance |
| F | Shares used to pay an exercise price or tax | No: often automatic |
| G | Gift | No |
| D | Sale or transfer back to the company | No |
| J | Other, explained in a footnote | Read the footnote |
The SEC's Form 4 instructions list every code. These are the ones you'll see most.
Traps that make a filing look like buying
- Offerings and placements coded P. An insider buying in an IPO or a private placement pays the deal price, not the market price. The footnote usually says so.
- Exercises described as purchases. Shares that came from exercising a warrant or option were bought at a price agreed long ago.
- Typos. Filers sometimes put the wrong figure in the price field. A price far from where the stock trades is worth checking against the original filing.
How AlphaFilings handles it
Purchases that turn out to be offerings, exercises or likely filing errors are left off the list automatically. The checks are automated, and can occasionally miss an edge case, so every purchase links to its filing.
See today's open-market buys →
Questions
- What does code P mean on a Form 4?
- A purchase on an exchange or from another person. Most are open-market buys, but some are private purchases.
- What does code F mean?
- Shares delivered or withheld to pay an option's exercise price or the tax on vested shares. It isn't a decision to sell.
- What does code M mean?
- Exercise or conversion of a derivative security, such as stock options received from the company.
Updated 2026-11-02. Rules and deadlines are summarised from the SEC's own guidance; check the SEC's pages for the full requirements. This page is general education, not investment advice.