The 8-K Trading Gap: Four Business Days Before the Filing

A company can learn something material on a Monday and not have to tell the public until Friday. The 8-K trading gap is that stretch: the period between a reportable event and the Form 8-K that discloses it, which is generally four business days. Insiders are not frozen during it. They can legally trade if they hold no material nonpublic information, and they cannot if they do. The filing calendar alone does not tell you which.

If you already read Form 4 (our Form 4 guide covers the basics), this is the second clock to put next to it. Here is how the gap works, what academic research found inside it, where the law draws the line, and how to compare the dates on EDGAR.

What the 8-K Trading Gap Is

General Instruction B.1 of Form 8-K says that unless otherwise specified, a report is filed or furnished within four business days after the event occurs. If the event lands on a weekend or holiday, the count starts on the next business day. The SEC considered a two-day deadline and, per the Cohen, Jackson and Mitts paper, decided in 2004 not to adopt it, keeping four business days.

Now overlay Form 4. Under Rule 16a-3(g)(1), a Form 4 is due before the end of the second business day after the transaction. The timeline below applies both rules to a hypothetical Monday event. The overlay is our inference, not a figure from any source.

Holidays and weekends shift the dates, and nothing requires a company to wait the full four days. Many file sooner.

Which 8-K Events Create a Gap (and Which Do Not)

The four-day clock in the form’s instructions applies to events in Sections 1–6 and 9, which cover things like agreements, acquisitions, bankruptcy, auditor changes and executive departures. Two items are treated differently. Item 1.05 (cybersecurity incidents) starts its clock when the company determines the incident is material, not when it happens. And information furnished under Item 2.02 (earnings) or Item 7.01 (Regulation FD) is not deemed “filed”, which is a liability distinction, not a timing exception.

What the Research Found: 15,419 8-Ks and 42 Basis Points

In 2015, Alma Cohen, Robert Jackson and Joshua Mitts published “The 8-K Trading Gap.” They built a dataset of 15,419 Form 8-Ks with insider trades in the gap, covering 42,820 trades from 2004 onward, and found abnormal returns of 42 basis points on average per trade. For open-market purchases of the insider’s own stock, the figure was 163 basis points. A Columbia Law School summary frames the sample as covering 2004 to 2014.

The paper also reports that trades in longer gaps were associated with higher profits. The study prompted Rep. Carolyn Maloney to call the results “very troubling” and announce plans for legislation, which we cover below.

Case Study: Equifax and Jun Ying

The illegal end of the spectrum looks different. In March 2018 the SEC charged Jun Ying, a former chief information officer of a U.S. business unit of Equifax who was next in line to be global CIO. The SEC alleged he used confidential information to conclude Equifax had suffered a serious breach, then exercised all his vested stock options and sold the shares for nearly $1 million before the breach was announced, avoiding more than $117,000 in losses. The breach affected about 148 million U.S. customers.

The consent final judgment entered June 28, 2019 included a ten-year bar from serving as an officer or director of a public company and a permanent injunction. In the parallel criminal case, Ying pleaded guilty, received a four-month prison sentence and forfeited $117,117. The lesson is about what he knew, not when the filing was due: the trade was a problem because of the information behind it.

Cyber Incidents: Item 1.05 and the Trading Ban the SEC Chose Not to Write

In July 2023 the SEC adopted rules requiring Item 1.05 disclosure of material cybersecurity incidents within four business days after a company determines the incident is material. Disclosure may be delayed if the U.S. Attorney General determines immediate disclosure would pose a substantial risk to national security or public safety. The earliest compliance date for the 8-K requirement was December 18, 2023, with an additional 180 days for smaller reporting companies.

Some commenters asked for a trading ban during the determination period. The adopting release declined: “We are not including a new rule to ban trading by insiders during the materiality determination time period.” It reasoned that, given the four-business-day deadline, “the risk of insider trading is low given the limited time period” between a material incident and disclosure. It also pointed to the new Rule 10b5-1 certification condition for directors and officers.

Earlier evidence suggests the stakes were not hypothetical. A study of 192 cyberattacks at 120 public companies from 2010 to 2015 sorted them into 101 Disclosing, 33 Withholding and 58 Immaterial cases. Net insider selling grew as outside discovery approached only at the Withholding firms.

Why a Gap-Period Trade Is Not Automatically Illegal

The legal test is not the calendar. The SEC’s 2018 cybersecurity guidance restates it: it is illegal to trade “on the basis of material nonpublic information about that security or issuer, in breach of a duty of trust or confidence.” Three common situations sit outside that line:

• The insider has no MNPI. Many 8-K events, such as routine governance changes, may not be material or known to the trader.
• A pre-set plan. Under Rule 10b5-1, directors and officers face a cooling-off period of the later of 90 days or two business days after the 10-Q or 10-K for the quarter of adoption, capped at 120 days, and must certify they were unaware of MNPI at adoption. Our 10b5-1 plan explainer covers the mechanics.
• Routine compensation. Scheduled awards appear on Form 4 but are not discretionary market bets (see our transaction code guide).

Companies can add their own guardrails. Columbia’s summary notes the authors suggest broader voluntary blackouts could help firms avoid insider-trading litigation. Our post on blackout periods explains how those windows usually work.

Congress Keeps Trying: The 8-K Trading Gap Act

Rep. Carolyn Maloney sponsored H.R. 4335, the 8-K Trading Gap Act of 2019. The House passed it 384–7 on January 13, 2020. Sen. Chris Van Hollen had introduced a Senate version in September 2019, and no Senate vote is reported there. The bill text shows it was referred to the Senate Banking Committee, and it did not become law.

Its design: add Section 10E to the Exchange Act, directing the SEC to require issuers to keep policies designed to stop executive officers and directors from trading while an 8-K event is pending, with rules due within one year of enactment. The restricted period would run from the event until filing for Items 1–6, and from when the issuer decides to disclose for Items 7 and 8. The SEC could exempt Rule 10b5-1 plans but not plans adopted during a restricted period. A Mintz analysis notes the bill would apply to all 8-K triggers regardless of materiality, and companies with noncompliant policies could face federal enforcement.

The 2024 reintroduction as the 8-K Trading Gap Act of 2024 has the same Section 10E structure. Sen. Van Hollen’s press release names Rep. Brad Sherman as the House co-introducer and says the Healthy Markets Association endorsed it. We could not confirm the status of any 8-K Trading Gap Act in the current Congress, so check Congress.gov before relying on any claim that a gap-closing rule is pending or in force. The sources reviewed show the 2020 bill was never enacted.

How to Check the 8-K Trading Gap Yourself on EDGAR

1. Find the 8-K.On the cover page, note the “date of report (date of earliest event reported)” and the filing date. The difference is the gap for that event.
2. Find the Form 4. Note the transaction date and the code. A P is an open-market purchase and an S an open-market sale, while compensation codes describe awards.
3. Compare. Did the transaction date fall between the event date and the 8-K filing date? If so, it sits inside that gap.
4. Check for a plan. Footnotes often say a trade was made under a 10b5-1 plan, which changes how it should be read.

Limits matter. The date of the event is not always the date a particular insider learned of it, the filing shows timing and not intent, and a trade inside a window can have an ordinary explanation. Our Exhibit 19 guide shows where to find a company’s own trading-window rules for comparison.

What the Gap Means for Reading Insider Signals

The practical point is context. A Form 4 viewed alone shows a trade; viewed with the 8-K calendar it shows whether the trade preceded public news. That is information about timing, and it is not a forecast. The research above describes average patterns across tens of thousands of trades, and the enforcement case describes what happens when specific confidential knowledge is involved. Neither tells you what any given filing means, and this post is not investment advice.