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  1. Home
  2. Glossary
  3. SEC Filings

Form 8-K

M
Marcus Thorne
Last Updated: January 5, 2026
Plain English Definition

SEC Form 8-K is a current report that companies must file to announce major events that shareholders should know about, including executive changes, acquisitions, earnings announcements, and other material corporate events.

The Trader's Take

The Signal

Form 8-K filings can trigger significant stock price movements, especially when they announce unexpected events like CEO departures, major acquisitions, or earnings surprises.

The Noise

Routine 8-K filings for minor corporate actions or standard disclosures may not impact stock price.

Actionable Insights

  • 1
    Monitor 8-K filings for executive changes—CEO or CFO departures can signal trouble.
  • 2
    Watch for 8-K filings announcing insider transactions or changes in beneficial ownership.
  • 3
    Major acquisitions or divestitures announced via 8-K can create trading opportunities.
  • 4
    Earnings announcements in 8-K filings often move markets immediately.

Regulatory Context & Context

Form 8-K must be filed within four business days of a triggering event. Required events include changes in control, material acquisitions or dispositions, changes in auditors, executive departures, and other material corporate events.
Timing / DeadlineReporting Requirement
4 Business DaysAfter the occurrence of a triggering event.

Common Misconceptions

Not all corporate events require an 8-K—only those specified by SEC rules.

8-K filings can be filed voluntarily for events not required by regulation.

The timing of 8-K filings can be strategic—companies may delay filing negative news.

Frequently Asked Questions

How quickly must Form 8-K be filed?

Form 8-K must be filed within four business days of the triggering event.

What types of events require Form 8-K filing?

Major events like executive changes, acquisitions, earnings announcements, auditor changes, and other material corporate events require Form 8-K filing.

On This Page

Trader's TakeRegulatory ContextCommon MisconceptionsF.A.Q.

Related Intelligence

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Form 10-K
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Form 10-Q
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Form DEF 14A

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