Generally shown as a disposition (D) to the issuer. The explanation or surrounding event must identify whether the covered obligation was an exercise price or tax liability.
Plain English
Securities were delivered or withheld to pay an exercise price or tax liability in a covered Rule 16b-3 event.
Common misread
Every code-F row is an open-market sale—or always tax withholding.
Grants, exercises, gifts, and other transfers can increase reported holdings without a code-P market purchase.
02
Disposed is not always sold
Issuer withholding, gifts, derivative conversion, and specialized transfers can reduce a row without a code-S sale.
03
Several rows can describe one event
Join dates, security types, ownership form, related tables, and footnotes before turning rows into a single description.
Read every code with its A/D indicator, security type, ownership form, footnotes, and related rows. The code begins the analysis; it does not finish it.
Common combinations
Event shapes you may see
P
Purchase
A market or private purchase; then test amount, price, role, timing, and holdings.
S
Sale
A market or private sale; plan status and holdings after help frame the event.
M + F
Exercise plus withholding
Underlying shares arrive through an exercise while securities settle an exercise price or tax obligation.
M + S
Exercise plus sale
An exercise is followed by market selling; connect both rows before describing retention.
A + F
Award plus withholding
Compensation shares are acquired and some securities may be withheld for a covered obligation.
G
Gift transfer
The A/D marker identifies the reporting person’s side; disposed does not turn a gift into a sale.
J
Other event
The explanation of responses is essential because J has no single universal economic meaning.
The same four questions, asked in the same order, every time. They are mechanics questions: none of them produces a verdict, and none of them is required to use the lookup above.
01
Which code is on the row?
The code, not the share count, decides what the event was.
02
Are other rows connected?
An exercise, a withholding, and a sale can all belong to one event. Same date, different codes, one story.
03
Is a 10b5-1 plan indicated?
Execution may follow instructions set months earlier.
04
What would make it ordinary?
Ask that before asking why it is notable.
Optional — all four are already listed above.
How this tool is built
Mechanics first, inference later
01
Official definitions
Code labels come from the current SEC Form 4 instructions.
02
Primary examples
Specific public examples are checked against the cited filing.
03
No motive claim
The tool explains what the filing reports, not why the reporting person acted.
04
No verdict
No code produces a recommendation, score, or directional conclusion.
05
Curated lookup
No filing URL is fetched or decoded. Verify the official filing before relying on a description.
Questions readers ask
Form 4 decoder FAQ
What is a Form 4 transaction code?
It is the letter in a Form 4 transaction row that classifies the event under the SEC’s instructions. Read it with the acquired/disposed marker, security type, related rows, and footnotes.
Which code means an open-market purchase?
Code P covers an open-market or private purchase. An acquired marker without code P may instead describe an award, exercise, gift, or another event.
Is code F always an insider sale?
No. Code F can report securities delivered or withheld for an exercise price or tax liability. It is a disposition, but it is not automatically code-S market selling.
Is code M the same as insider buying?
No. Code M identifies exercise or conversion of a derivative security. It is not a code-P purchase at the current market price, even when underlying share ownership rises.
Can one Form 4 contain several transaction codes?
Yes. One underlying event can produce connected rows—for example an option exercise under M plus issuer withholding under F, or an exercise followed by a sale under S.
Does a code reveal why the insider acted?
No. A transaction code classifies mechanics. Plan disclosures, footnotes, ownership changes, timing, and other evidence may add context, but the letter alone does not establish motive.
Can I paste a filing URL?
Not yet. This version provides a curated lookup for seven transaction codes and does not accept or decode filing URLs or accession numbers.
A filing-mechanics guide to separating option exercises, issuer withholding, and exercise-linked sales from a fresh decision to buy at the market price.
A Form 4 covering more than 300 million Tesla shares contained no open-market trade: an option exercise, a net-share settlement, and restricted stock scheduled to vest in 2028.
A large planned sale under a Rule 10b5-1 program adopted months earlier is not automatically a bearish statement about the current price.
8 min readReviewed
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Informational and educational only. Not investment advice. Buteon provides market data analysis and signal interpretation for informational and educational purposes. It is not a broker, custodian, or investment adviser, and this tool is not investment advice or a buy/sell recommendation. Always verify the official filing.