Form 4 transaction codes are one-letter SEC codes. They identify a purchase, sale, grant, tax payment, option exercise, gift, or another ownership change. Read the code first. Then use the other fields to understand the transaction.

Read the code with the security title, table, acquisition or disposition field, ownership type, and footnotes. The same filing can contain several codes that describe related parts of one event.

Quick reference: common Form 4 codes

  • P: Open-market or private purchase of a non-derivative or derivative security.
  • S: Open-market or private sale of a non-derivative or derivative security.
  • A: Grant, award, or other acquisition under Rule 16b-3(d).
  • D: Disposition to the issuer under Rule 16b-3(e).
  • F: Payment of an exercise price or tax liability by delivering or withholding securities in a Rule 16b-3 transaction.
  • M: Exercise or conversion of a derivative security exempt under Rule 16b-3.
  • X: Exercise of an in-the-money or at-the-money derivative security that does not use code M.
  • G: Bona fide gift.
  • J: Other acquisition or disposition. The filer must describe the transaction.
  • V: A separate indicator for a transaction reported voluntarily before it was required.

Start with codes P and S

Codes P and S identify open-market or private purchases and sales. They can apply to non-derivative or derivative securities. Check the security title and the table before you call a row a common-stock trade.

A code P row shows a purchase. It does not prove that the purchase occurred on a public exchange because the code also covers private purchases. A code S row shows a sale. Read a sale with its Rule 10b5-1 information, holdings after the transaction, ownership type, and footnotes.

Compensation and tax codes: A, F, and M

A large portion of Form 4 volume comes from compensation activity. Code A can report grants or awards. Code F can report shares delivered or withheld for an exercise price or tax liability. Code M reports an exercise or conversion that is exempt under Rule 16b-3. These rows are not the same as a code P purchase.

When reading these codes, look for linked rows. An option exercise may be followed by a sale. A stock award may be followed by tax withholding. Treat the full filing as a sequence, not as isolated rows.

Derivative codes

  • C: Conversion of a derivative security.
  • E: Expiration of a short derivative position.
  • H: Expiration or cancellation of a long derivative position when the holder receives value.
  • O: Exercise of an out-of-the-money derivative security.
  • X: Exercise of an in-the-money or at-the-money derivative security.

Other codes

  • G: Bona fide gift.
  • L: Small acquisition under Rule 16a-6.
  • W: Acquisition or disposition by will or the laws of descent and distribution.
  • Z: Deposit into or withdrawal from a voting trust.
  • J: Other acquisition or disposition. Read the description.
  • K: Equity swap or an instrument with similar characteristics. The filer uses K with the main transaction code when applicable.
  • U: Disposition in a tender of shares in a change-of-control transaction.

Code I does not mean a 10b5-1 trade. It means a discretionary transaction under Rule 16b-3(f). Code U does not mean a 10b5-1 trade. It describes a disposition in a change-of-control tender. Use the Form 4 Rule 10b5-1 checkbox, adoption date, and filing text to review plan status.

How The Insiders Post uses transaction codes

The Insiders Post keeps the interpretation filing-only. We use transaction codes to filter rows, group activity, and assign deterministic labels such as open-market purchase, open-market sale, tax withholding, option exercise, and grant. We do not treat a code as a prediction of future stock performance.

Cluster and repeated-purchase signals focus on code P. The product groups codes P and S as open-market activity for screening. The official definitions also include private purchases and sales. Check the filing when that distinction is important.

Common mistakes when reading Form 4 codes

  • Do not treat every acquisition as an open-market purchase. Grants, awards, and option exercises can increase holdings without a market buy.
  • Do not treat every sale as a negative signal. Sales can be scheduled, tax-related, or small relative to remaining holdings.
  • Do not ignore footnotes. Code J, indirect ownership, 10b5-1 language, and derivative activity often need footnote context.
  • Do not mix Form 144 proposed sales with Form 4 executed transactions. A Form 144 notice is not the same as a completed code S sale.
  • Do not compare dollar values blindly when price is missing or when the row is derivative-only.
The code describes the reported transaction. It does not state the insider's reason for the transaction.