1. What a Form 4 is and who files it
A Form 4 is a statement of changes in beneficial ownership. Directors, officers, and holders of more than 10% of a class of a company's securities — together called Section 16 insiders — must report transactions that change their beneficial ownership of the company's equity securities. Non-derivative securities (for example, common stock) go in Table I; derivative securities (options, warrants, convertible securities, and similar rights) go in Table II. Each transaction is reported on its own line, and each line carries a code describing the character of the transaction.
2. The two-business-day deadline
A Form 4 must be filed before the end of the second business day following the day on which the transaction was executed. That is a short fuse, and it is why insider data on this site moves fast: a trade on Monday is normally public by Wednesday. A Form 3, the initial statement when a person first becomes an insider, is due within 10 days of becoming an insider. A Form 5, the annual statement, is due within 45 days after the issuer's fiscal year ends and is only required when something was exempt from earlier reporting or was not reported during the year; when insiders report on Form 5, they use the same transaction codes as on Form 4. A transaction that belongs on Form 5 may instead be reported early on a Form 4.
3. Form 3 vs. Form 4 vs. Form 5
| Form | When | What it covers |
|---|---|---|
| Form 3 | Within 10 days of becoming an insider | Initial holdings |
| Form 4 | Before the end of the second business day after execution | Changes in beneficial ownership |
| Form 5 | Within 45 days after fiscal year-end, only when needed | Exempt or previously unreported transactions and holdings |
Only two codes describe an insider buying or selling on the open market or in a private deal: P (purchase) and S (sale). Everything else on the form is compensation, an option exercise, a gift, an inheritance, or an administrative case. That is why this site's insider screens are built on P and S rows only: a cluster of P rows is insiders spending their own money, and a cluster of S rows is insiders selling. When you see a headline about "insider buying," check that the underlying rows are code P — a headline built on code A (a grant) or code M (an option exercise) is describing pay, not a purchase decision.
5. The full code table (20 codes)
The table below reproduces the code list from Instruction 8 of the Form 4 General Instructions (SEC 1475), grouped as the instructions group them.
| Code | Meaning |
|---|---|
| P | Open market or private purchase of nonderivative or derivative security |
| S | Open market or private sale of nonderivative or derivative security |
| V | Transaction voluntarily reported earlier than required |
| A | Grant, award, or other acquisition pursuant to Rule 16b-3(d) |
| D | Disposition to the issuer of issuer equity securities pursuant to Rule 16b-3(e) |
| F | Payment of exercise price or tax liability by delivering or withholding securities incident to the receipt, exercise, or vesting of a security issued in accordance with Rule 16b-3 |
| I | Discretionary transaction in accordance with Rule 16b-3(f) resulting in acquisition or disposition of issuer securities |
| M | Exercise or conversion of derivative security exempted pursuant to Rule 16b-3 |
| C | Conversion of derivative security |
| E | Expiration of short derivative position |
| H | Expiration (or cancellation) of long derivative position with value received |
| O | Exercise of out-of-the-money derivative security |
| X | Exercise of in-the-money or at-the-money derivative security |
| 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 voting trust |
| J | Other acquisition or disposition (describe the transaction) |
| K | Transaction in equity swap or instrument with similar characteristics (used in addition to the code that best describes the transaction, for example S/K or P/K) |
| U | Disposition pursuant to a tender of shares in a change of control transaction |
If a transaction is not specifically listed, the filer uses code J and describes it in the explanation of responses. If a transaction is voluntarily reported earlier than required, the filer marks it V. If a transaction involves an equity swap or similar instrument, the filer adds K alongside the main code.
6. Compensation codes: A, M, F, X
Grants (A), exercises of exempt derivatives (M), tax withholding by share delivery (F), and exercises of in- or at-the-money derivatives (X) are the most common non-market rows. They appear constantly in insider filings because executive pay is delivered in stock and options. None of them means the insider chose to buy shares with cash at the market price. Treating an A or M row as a purchase overstates insider conviction; treating an F row as a sale overstates insider pessimism, since the "sale" is often just the tax bill on a vesting grant.
7. Gifts, inheritances, and other codes (G, W, J, K, V and the rest)
Bona fide gifts (G) are reportable on Form 4, as are acquisitions or dispositions by will or descent (W) and deposits into or withdrawals from a voting trust (Z). Small acquisitions under Rule 16a-6 carry code L. Code J is the residual bucket for anything not specifically listed, and it must be explained in words — a J row without reading its footnote is unreadable. Code K never stands alone: it rides along with the main code to flag that the transaction is an equity swap or similar hedge, which matters because a hedged "purchase" may not carry the economic exposure its headline suggests.
8. The Rule 10b5-1 checkbox
The current Form 4 asks the filer to check a box when a transaction was made under a contract, instruction, or written plan intended to satisfy the affirmative defense conditions of Rule 10b5-1(c), and to give the plan's adoption date in the Explanation of Responses. That checkbox is the marker this site's 10b5-1 research builds on: it separates trades the insider scheduled in advance from trades the insider chose in the moment. A checked box does not make a trade innocent or guilty — it says the trade was made under a plan the filer claims meets the rule's conditions.
9. What changed: the 2022 amendments and the 2026 foreign-insider rules
Two sets of changes explain why older Form 4s look different from newer ones.
The 2022 Rule 10b5-1 amendments. On December 14, 2022, the SEC adopted amendments to Rule 10b5-1 and to Forms 4 and 5. The final rules became effective February 27, 2023, and Section 16 reporting persons were required to comply with the Form 4 and 5 amendments for beneficial ownership reports filed on or after April 1, 2023. Two changes matter most for reading Form 4s. First, dispositions of equity securities by bona fide gifts, which had previously been permitted to be reported on Form 5, must now be reported on Form 4 — so a code G row after April 2023 is on the fast two-business-day clock, not the annual form. Second, the amendments added mandatory cooling-off periods before trading can begin under a Rule 10b5-1 plan: for directors and officers, the later of 90 days after adoption of the plan and two business days following disclosure of the issuer's financial results in a Form 10-Q or Form 10-K for the completed fiscal quarter in which the plan was adopted (for foreign private issuers, in a Form 20-F or Form 6-K disclosing financial results), subject to a maximum of 120 days after adoption; for persons other than the issuer and other than directors and officers, 30 days after adoption. That is why the plan adoption date disclosed in the Explanation of Responses matters: it starts the clock that the cooling-off period measures.
The 2026 foreign-insider rules (HFIA). The Holding Foreign Insiders Accountable Act, enacted December 18, 2025, extended Section 16(a) reporting to directors and officers of foreign private issuers with a class of equity securities registered under Section 12 of the Exchange Act. The SEC adopted conforming final rules on February 27, 2026, effective March 18, 2026. From that date, directors and officers of such issuers must file Section 16 reports electronically and in English. Holders of more than 10% of a foreign private issuer's securities are not covered by this extension: the final rules amend Rule 16a-2 to exclude them from the Section 16(a) requirements for such issuers. The forms also gained an optional second trading-symbol field — Box 2a on Forms 4 and 5 (Box 3a on Form 3) — for issuers traded in both U.S. and non-U.S. markets, and clearer country designation for reporting persons with foreign addresses. For readers, the practical effect is that Form 4 coverage widened in 2026: trades by foreign private issuer directors and officers that previously never appeared on Form 4 now do.
10. What this site shows — and what the full Form 4 record looks like
This site's insider screens use Form 4 code P rows for buys and code S rows for sells. That filter is deliberate: it is the only pair of codes that directly reflects an insider's own buying or selling decision.
The table below is a census of this site's own parsed Form 4 corpus (not the tracked-stock universe: it covers every issuer in the corpus), as of corpus cutoff 2026-10-02. It counts transaction-code rows by filing date. The corpus holds 316,796 parsed filings dated 2025-01-02 to 2026-10-02; the window below is the same 90-day window as the site's insider screens (filings dated 2026-07-31 to 2026-10-29, effectively through the corpus cutoff of 2026-10-02).
| Code | Rows in window | What it is |
|---|---|---|
| S | 19,856 | Open market or private sale |
| A | 12,092 | Grant / award |
| M | 11,797 | Exercise / conversion of exempt derivative |
| F | 5,276 | Exercise price / tax paid in shares |
| P | 4,368 | Open market or private purchase |
| D | 1,731 | Disposition back to the issuer |
| J | 1,524 | Other (described in words) |
| C | 1,326 | Conversion of derivative |
| G | 958 | Bona fide gift |
| X | 108 | Exercise of in-/at-the-money derivative |
| L | 49 | Small acquisition (Rule 16a-6) |
| E | 40 | Expiration of short derivative position |
| U | 28 | Tender in a change of control |
| I | 27 | Discretionary transaction (Rule 16b-3(f)) |
| W | 14 | Will / descent |
| Z | 11 | Voting trust deposit / withdrawal |
| H | 1 | Expiration of long derivative position with value |
| O | 1 | Exercise of out-of-the-money derivative |
| V | 0 | Voluntarily reported early (see note) |
Total rows in window: 59,207 across 25,512 filings. Two readings follow. First, sales outnumber purchases by more than four to one (19,856 S vs. 4,368 P) — the familiar asymmetry of insider data, where selling is routine diversification and buying is the rarer event. Second, compensation rows outnumber market rows: grants, exempt exercises, and tax withholding (A + M + F = 29,165) exceed purchases plus sales (P + S = 24,224). Anyone counting "insider transactions" without splitting by code is mostly counting pay.
Note on code V: it never appears as a stored code in this corpus, because V is a flag added to a transaction that is voluntarily reported early, not a standalone transaction type — the underlying transaction still carries its own code. Note on coverage: this census counts all issuers in the parsed corpus, while the site's insider screens cover only the tracked stock universe, so these totals are larger than the P/S rows behind the site's ticker pages.
See also: Insider cluster buying · 10b5-1 plan age · Insider clusters, 30 days · Insider sell clusters · Methodology.
Frequently asked questions
What does code P mean on a Form 4? Code P marks an open market or private purchase of the security. Together with code S (open market or private sale), it is the code most directly tied to an insider buying or selling on their own decision.
What is the difference between codes M, F, and A? A is a grant or award from the company under Rule 16b-3, and M is the exercise or conversion of an exempt derivative such as an option. F means paying an exercise price or tax bill by handing over or withholding shares.
How fast must a Form 4 be filed? Before the end of the second business day after the transaction is executed. A Form 3 is due within 10 days of becoming an insider, and a Form 5, when needed, within 45 days after fiscal year-end.
What is the Rule 10b5-1 checkbox? The filer checks a box when a reported trade was made under a plan intended to satisfy the Rule 10b5-1(c) affirmative defense, and must also give the plan's adoption date in the Explanation of Responses.
Are gifts of stock reported on Form 4 now? Yes. Bona fide gifts (code G) are listed among the transactions that must be reported on Form 4.
Did gifts used to be reported on Form 5? Yes. Before the 2022 amendments, bona fide gifts could be reported on Form 5. For reports filed on or after April 1, 2023, gift dispositions must be reported on Form 4.
What is the Rule 10b5-1 cooling-off period? It is the waiting period between adopting (or modifying) a Rule 10b5-1 plan and the first trade under it: for directors and officers, the later of 90 days after adoption and two business days after disclosure of financial results for the quarter of adoption, capped at 120 days; for other persons (other than the issuer), 30 days.
Do directors and officers of foreign private issuers file Form 4 now? Yes, since March 18, 2026, under the Holding Foreign Insiders Accountable Act rules — but only directors and officers, not holders of more than 10% of the issuer's securities.
Sources
- SEC, Form 4 General Instructions (SEC 1475), Instruction 1(a) (second-business-day deadline), Instruction 4 (reportable transactions including bona fide gift dispositions), Instruction 8 (all 20 transaction codes), Instruction 10 (Rule 10b5-1(c) checkbox and plan adoption date). https://www.sec.gov/files/form4data.pdf (checked 2026-10-29; the copy served was crawled 2026-02-14 and carries the header SEC 1475 (02-25)) - SEC Office of Investor Education and Advocacy, Updated Investor Bulletin: Insider Transactions and Forms 3, 4, and 5 (common codes A, K, P, S, D, F, M, G, V, J; Form 3 within 10 days; Form 4 within two business days; Form 5 within 45 days after fiscal year-end using the same codes). https://www.investor.gov/news-alerts/investor-bulletins/investor-bulletin-insider-transactions-forms-3-4-5 (checked 2026-10-29) - 17 CFR 240.16a-3 (Form 4 due before the end of the second business day after execution; Form 5 within 45 days after fiscal year-end; Form 5 transactions may be reported early on Form 4). https://www.ecfr.gov/current/title-17/chapter-II/part-240/subject-group-ECFR451036c2752e741/section-240.16a-3 (checked 2026-10-29)
- SEC, "SEC Adopts Amendments to Modernize Rule 10b5-1 Insider Trading Plans and Related Disclosures," Press Release 2022-222 (adopted December 14, 2022; Forms 4 and 5 compliance for reports filed on or after April 1, 2023; bona fide gifts moved from Form 5 to Form 4). https://www.sec.gov/news/press-release/2022-222 (checked 2026-10-29) - SEC, Insider Trading Arrangements and Related Disclosures, Release Nos. 33-11138 / 34-96492 (effective February 27, 2023; Federal Register publication December 29, 2022). https://www.sec.gov/rules-regulations/2022/12/insider-trading-arrangements-related-disclosures (checked 2026-10-29) - SEC, Small Entity Compliance Guide: Insider Trading Arrangements and Related Disclosures (February 24, 2023; effective date February 27, 2023; Form 4/5 compliance April 1, 2023; gifts on Form 4 rather than Form 5). https://www.sec.gov/resources-small-businesses/small-business-compliance-guides/insider-trading-arrangements-and-related-disclosures (checked 2026-10-29) - 17 CFR 240.10b5-1(c)(1)(ii)(B) (cooling-off periods: directors and officers, later of 90 days / two business days after financial-results disclosure, maximum 120 days; other persons, 30 days). https://www.ecfr.gov/current/title-17/chapter-II/part-240/section-240.10b5-1 (checked 2026-10-29) - SEC, "SEC Adopts Final Rules for the Holding Foreign Insiders Accountable Act," Press Release 2026-23 (adopted February 27, 2026; FPI directors and officers to begin disclosing March 18, 2026; 10 percent holders excluded). https://www.sec.gov/newsroom/press-releases/2026-23-sec-adopts-final-rules-holding-foreign-insiders-accountable-act (checked 2026-10-29) - SEC, Holding Foreign Insiders Accountable Act Disclosure, Release No. 34-104903 (effective March 18, 2026; Rule 16a-2 exclusion of FPI 10 percent holders; optional Box 2a second trading symbol; clearer country designation for foreign-address filers). https://www.sec.gov/files/rules/final/2026/34-104903.pdf (checked 2026-10-29)
Last updated: 2026-10-29. This is general information about a disclosure form, not tax, investment, or legal advice.
For education only — not investment advice. How every number on this site is measured: Methodology.