SEC Form 4 Transaction Codes: A Complete Reference
Every transaction on a Form 4 is tagged with a single-letter code that tells you what kind of trade it was. Learning to read these codes is the fastest way to separate meaningful signals from routine compensation noise.
A code of P (an insider spending real money to buy) means something very different from an A(shares handed out as salary). Both increase an insider's holdings, but only one reflects a deliberate investment decision. Below is a full reference, grouped by category, with our read on how much signal each code typically carries.
The Two Codes That Matter Most: P and S
If you learn only two codes, make them these. A P is an open-market purchase — the insider chose to buy, with their own capital, at the market price. It is the single most-watched code in insider data because it reflects genuine conviction. An S is an open-market sale. Sales are noisier (insiders sell for countless personal reasons), but a pattern of heavy selling can still be worth investigating.
| Code | Meaning | Signal |
|---|---|---|
| P | Open-market purchase. The insider bought shares on the open market or in a private transaction with their own money. | High |
| S | Open-market sale. The insider sold shares on the open market or privately. | Medium |
| V | Voluntary early report. A transaction the insider chose to report earlier than required. | Context |
Compensation & Rule 16b-3 Codes
These codes reflect the mechanics of executive pay rather than market conviction. An insider's holdings may jump because of an A grant or an M option exercise — but no open-market buying decision was made. The F code, in particular, often appears alongside vesting events, when shares are withheld to cover taxes.
| Code | Meaning | Signal |
|---|---|---|
| A | Grant / award. Shares or units granted as compensation (e.g., RSUs), not purchased. | Low |
| M | Option exercise / conversion. Exercise or conversion of a derivative security into shares. | Low |
| F | Tax / exercise-price withholding. Shares surrendered to cover taxes or the cost of exercising options. | Low |
| D | Disposition to issuer. Securities returned to or repurchased by the company. | Low |
| I | Discretionary transaction. A trade under an employee benefit plan (e.g., a 401(k) fund switch). | Low |
Derivative Security Codes
These describe activity in options, warrants, and other derivatives. They're common and usually mechanical, but the context matters — an X exercise of an in-the-money option followed by an immediate S sale is a different story than an exercise where the insider keeps the shares.
| Code | Meaning | Signal |
|---|---|---|
| C | Conversion of derivative. A derivative security converted into the underlying stock. | Context |
| X | Exercise of in/at-the-money option. Exercise of a derivative that has intrinsic value. | Context |
| O | Exercise of out-of-the-money option. Exercise of a derivative with no intrinsic value. | Context |
| E | Expiration of short position. A short derivative position expired. | Low |
| H | Expiration of long position. A long derivative position expired or was cancelled for value. | Low |
Gifts & Other Codes
The remaining codes cover gifts, inheritance, and edge cases. A G gift, for instance, moves shares without any market transaction — often for estate planning or charitable giving — and carries little directional signal.
| Code | Meaning | Signal |
|---|---|---|
| G | Bona fide gift. Shares given away — to family, a trust, or charity. No cash changes hands. | Low |
| W | Will / inheritance. Acquisition or disposition by will or the laws of descent. | Low |
| J | Other. A transaction that doesn't fit the standard codes; see the filing footnotes. | Context |
| Z | Voting-trust movement. Deposit into or withdrawal from a voting trust. | Low |
Putting It Together
When you scan a Form 4, glance at the code first. Filter for Pcodes when you're hunting for conviction buys; treat A, M, and Fas compensation background; and always read the filing's footnotes, which frequently explain the J "other" transactions in plain language. For a broader walkthrough of the full filing layout, see How to Read SEC Insider Trading Data.