Form 4 (Insider Transaction)
// SEC filing of an insider trade in the issuer's securities, due within 2 business days
Form 4 is the SEC filing that a Section 16 insider (officer, director, or 10%+ beneficial owner) must submit within two business days of any transaction in the issuer's securities. The filing publishes to EDGAR in near real time after acceptance.
- Two-business-day filing deadline per Section 16(a) of the Exchange Act.
- Tapeboard polls the EDGAR Form 4 RSS feed at sub-90-second intervals and alerts on every filing.
- Insider buys are usually more informative than sells (sales can be diversification, taxes, or scheduled 10b5-1 plan executions).
How it is calculated
Form 4 carries the transaction code in column 3, which is the most important field after the share count and price. P (open-market purchase) is the cleanest insider signal. M (option exercise) and A (grant) are mechanical. S (sale) is ambiguous without further context. 10b5-1 plans are pre-scheduled; a 10b5-1 sale is not a discretionary trade.
What traders use it for
- Catching insider buying clusters. Multiple officers buying within a week is a stronger signal than one director buying in isolation.
- Filtering noise. Form 4 sales are often 10b5-1-plan executions; checking the filing for the 10b5-1 indicator separates discretionary sells from scheduled ones.
- Catalyst-pairing. An insider purchase before an 8-K announcement is a particularly strong signal once the 8-K resolves the timing.
Worked example
On 2026-05-01 16:38 ET, a Form 4 prints from an NVDA director: 12,000 shares purchased at an average price of $897.42, transaction date 2026-05-01, transaction code P (open-market purchase). The filing arrived sub-90 seconds after EDGAR acceptance. The director's prior Form 4 was an A (stock grant) eight months earlier; this is the first open-market P from this insider. As of 2026-05-01 16:38 ET. A first open-market purchase by a long-standing director on no announcement is the kind of pattern Tapeboard flags as a high-conviction insider signal.
Live data: /stocks/NVDA.
Common pitfalls
- Sale signals are mostly diversification or 10b5-1 plans. Reading every Form 4 sale as bearish overstates the signal; check for the 10b5-1 indicator on the filing.
- Insider buys via option exercise (code M) are not the same as open-market purchases (code P). The M code reflects pre-existing economic exposure being converted; P is new dollars being put to work.
- 10%+ beneficial owners include institutional vehicles. A Form 4 from a hedge fund crossing the 10% threshold is a very different signal from a director's personal-account buy.
- Late filings happen. The two-business-day rule is a hard rule, but enforcement is not instantaneous; check the transaction date versus filing date for late-filed Form 4s.
Where this metric appears on Tapeboard
Form 4 alerts route through every `/stocks/{T}` ticker page (insider-activity panel), the /insider screener, and the /filings stream. Sub-90-second alerting is the default for paid users.
Related terms
- Short Interest: FINRA short-interest reports settle bi-monthly with a publication lag of about 10 business days from the report date.
- Options Flow: OPRA is the consolidated US options price-reporting authority; every executed options trade reports to OPRA in real time.
Primary sources cited
- SEC Form 4 filing rule (Section 16): Form 4 must be filed within two business days of the insider transaction per Section 16(a) of the Exchange Act. https://www.sec.gov/about/forms/form4.pdf, retrieved 2026-05-04.
- SEC EDGAR full-text search documentation: SEC EDGAR publishes Form 4 filings via RSS within seconds of acceptance. https://www.sec.gov/edgar, retrieved 2026-05-04.
Methodology last reviewed 2026-05-04 by Marcus Reilly, Editor at Tapeboard. Every claim on this page has a row in the citation registry. Glossary terms reverify on the Jan 15 / Apr 15 / Jul 15 / Oct 15 cron and any time the underlying primary-source publishes a methodology change. See methodology for the full fact-check process and corrections for the public correction log.
Disclaimer. This page is for educational and informational purposes only. Nothing on Tapeboard is investment advice. See the full risk disclaimer.