SEC Form 4 transaction codes: what P, S, A, M, F, G and the other letters mean
By OQRO. Published . 4 min read. Last reviewed .
The short answer
On an SEC Form 4, P means a purchase and S means a sale, and most other letters mark events that are not trades in the market: A is a grant, M an option exercise, F shares withheld for tax, G a gift. In the 90 days to 9 October 2026, OQRO, a tracker of SEC and congressional disclosures, stored 40,124 insider transaction records, and 6.0% of them were open-market purchases.
Where the code is
Each line of Table I (shares) and Table II (options and other derivatives) on a Form 4 carries a transaction code. The list is in General Instruction 8 of the SEC's Form 4. The instruction says to use the code that most appropriately describes the transaction, to use J when none fits and explain it in the form's explanation of responses, and to add V when a transaction was reported voluntarily earlier than required.
The full list
| Code | What the SEC's instructions say it is | A trade in the market? |
|---|---|---|
| P | Open market or private purchase of a security | Yes, but it can be a private purchase |
| S | Open market or private sale of a security | Yes, but it can be a private sale |
| A | Grant, award or other acquisition under Rule 16b-3(d) | No, it comes from the company |
| D | Disposition to the issuer under Rule 16b-3(e) | No, a sale back to the company |
| F | Payment of exercise price or tax by delivering or withholding securities | No |
| I | Discretionary transaction under Rule 16b-3(f) | Depends on the plan |
| M | Exercise or conversion of a derivative exempted under Rule 16b-3 | No, it converts an option |
| C | Conversion of a derivative security | No |
| X | Exercise of an in-the-money or at-the-money derivative | No |
| O | Exercise of an out-of-the-money derivative | No |
| E | Expiration of a short derivative position | No |
| H | Expiration or cancellation of a long derivative position with value received | No |
| G | Bona fide gift | No |
| L | Small acquisition under Rule 16a-6 | No |
| W | Acquisition or disposition by will or the laws of descent | No |
| Z | Deposit into or withdrawal from a voting trust | No |
| J | Other acquisition or disposition, described in a footnote | Read the footnote |
| K | Equity swap or similar instrument, written with another code such as S/K | Hedging, read the footnote |
| U | Disposition in a tender of shares in a change of control | No |
| V | Reported voluntarily earlier than required, an add-on to another code | Depends on the code |
Three things the letters hide
P and S include private deals. The instructions describe P and S as open market or private. A purchase from another shareholder in a negotiated deal is also a P. The footnotes say which it was.
M is usually followed by something else. An executive who exercises options reports the exercise as an M line in Table II, and the resulting shares arrive in Table I. Seeing new shares with no P next to them is normal.
F is a bookkeeping line. When shares are withheld to pay tax on a vesting award, the form shows a disposal, but the insider did not choose a sale price or a moment. That is the main reason a column of F lines should not be read as selling.
How common each kind is
OQRO reads each Form 4 and sorts every transaction into a plain class. The class starts from the code, but the footnotes and the table decide it, as the methodology explains. For transactions dated from 11 July to 9 October 2026, counted on 9 October 2026 and excluding Form 144 planned sales:
| OQRO class | Records | Share |
|---|---|---|
| Open-market sale | 13,250 | 33.0% |
| Grant or award | 9,667 | 24.1% |
| Option exercise | 8,678 | 21.6% |
| Tax withholding | 3,819 | 9.5% |
| Open-market purchase | 2,417 | 6.0% |
| Other | 1,672 | 4.2% |
| Gift or transfer | 621 | 1.5% |
| All insider transaction records | 40,124 | 100% |
A record is one transaction line. This is a count of what was filed in one quarter, so another period would give other proportions. It does show why a feed of every line is mostly grants, exercises and tax withholding, and why OQRO separates the purchases and sales that were decisions from the lines that were not.
What a code does not tell you
A code says what kind of event happened, not why. A sale coded S may sit inside a trading plan; the Form 4 has a separate check box for that, explained in Rule 10b5-1 plans. A P is the line most readers care about, and the guide to open-market purchases explains what it does and does not show.
Treat the code as the first filter and the footnotes as the second. The deadline for filing the form is explained in when is a Form 4 late.
Sources
- SEC Form 4 and General Instructions (instruction 8, transaction codes) (opened October 9, 2026)
- SEC Investor Bulletin: Insider Transactions and Forms 3, 4, and 5 (opened October 9, 2026)
- OQRO methodology (opened October 9, 2026)
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This explains public filings in plain words. It is not legal or investment advice. Corrections: contact page.