Insider disclosures
Form 4 Transaction Codes: P, S, A, M and F Explained
Before describing an insider transaction as “buying” or “selling,” check what kind of transaction the filing reports. An award, an option exercise and shares withheld for taxes answer different questions from a purchase or sale.
A quick guide to five codes
These are compact explanations, not the full list of Form 4 codes:
| Code | Meaning |
|---|---|
| P | A purchase, either in the open market or privately |
| S | A sale, either in the open market or privately |
| A | A grant, award or other acquisition under Rule 16b-3(d) |
| M | An exercise or conversion of a derivative security exempt under Rule 16b-3 |
| F | Securities delivered or withheld to cover an exercise price or tax obligation connected with a qualifying receipt, exercise or vesting |
P and S can apply to derivative or non-derivative securities. For the complete definitions and the other codes, see Form 4 instructions, Instruction 8; Investor.gov's bulletin on Forms 3, 4 and 5 gives a shorter plain-English list.
The distinction matters when writing a summary. A label such as “shares acquired” is a starting observation. It is not, by itself, an explanation of how or why the person acquired them.
Once you have identified the company in a filing, OpenBit's stock research page is a next stop for company research. Bring the company name and your unanswered question; use the original Form 4 to establish the transaction details.
Two different columns can contain “A”
The transaction-code column describes the transaction type. A separate acquired/disposed field records direction: A for acquired, D for disposed. An A in that direction field does not establish that the transaction code is A. Read the column heading before interpreting the letter. Form 4, Table I, columns 3 and 4
When making notes, use two fields: transaction type and acquired or disposed. Keeping both prevents a short headline from erasing the difference between an award and a purchase.
An F transaction needs its own explanation
Consider this hypothetical example, not a real filing:
- The explanation says a stock award delivered 1,000 shares.
- It also says 300 shares were withheld to meet the associated tax obligation.
- Assume no other transactions for this example. The net addition is 700 shares.
“The person sold 300 shares because they expect the stock to fall” adds a motive the example does not support. “The person bought 1,000 shares in the market” also misstates what happened.
A useful summary keeps the events connected: the person received an award, part was withheld for the stated obligation, and the net addition in this example was 700 shares. Do not substitute that arithmetic for the filing's actual holdings figures in a real case; first reconcile all relevant rows and explanations.
Read the rows and footnotes together
Work through the filing in this order:
- Identify the person and company. Avoid confusing two people or different ownership arrangements.
- Record the transaction date. Keep it separate from the filing date and the date you found the filing. A Form 4 is generally due before the end of the second business day after the transaction; if the gap looks longer, read the explanation before drawing a conclusion. Form 4, General Instruction 1(a)
- Name the security. Write down what is actually being transferred or exercised.
- Capture code, direction, amount and price. Do not reduce the record to one positive or negative number.
- Read every linked explanation. Look for related rows, the stated reason for withholding, and details needed to understand a displayed price.
- Write the unanswered question. If the record does not establish a motive, leave the motive unknown.
Form 4 also includes a checkbox for transactions under a plan intended to meet Rule 10b5-1(c)'s affirmative-defense conditions. Record that context without treating the checkbox as a verdict about legality or investment merit. Form 4, cover page and Instruction 10
A reusable transaction note
Use this format before sharing a conclusion:
On [transaction date], [person] reported [transaction type] involving [security and amount]. The filing's explanation states [relevant context]. After reconciling related rows, I understand the event as [plain-language description]. The filing does not establish [remaining uncertainty]. Source: [original filing link].
For example, your remaining uncertainty might be how the event relates to compensation, a broader ownership arrangement or the company's business outlook. Those are separate research questions; a single code will not answer them.
Finish by checking whether your headline says more than your note can support. An accurate description makes a better starting point for company research than an assumed bullish or bearish signal.
Investigate the business behind the transaction
Open OpenBit's research question page to continue from the transaction to the business. A useful question to take with you is: “What evidence would support or weaken my view of this company?” Replace “this company” with the company you are researching.
If you are also looking at a fund manager's holdings, read our guide to interpreting a 13F filing. It explains why a quarterly holdings snapshot needs a different reading from an individual transaction report.