What is a Form 8-K? Definition, Triggers, and Example
A Form 8-K is the SEC filing a public company must submit within four business days of a material event — earnings, mergers, CEO changes, bankruptcy — making it the fastest official source of market-moving news.
What is a Form 8-K?
A Form 8-K is the "current report" U.S. public companies file with the Securities and Exchange Commission to disclose material events between their quarterly and annual reports. Unlike the 10-K, which arrives once a year, an 8-K is event-driven: when something happens that a reasonable investor would consider important — an earnings release, an acquisition, a CEO resignation, a bankruptcy filing — the company must file an 8-K within four business days of the event. It is the primary legal mechanism that keeps public-company disclosure continuous rather than periodic.
What Triggers an 8-K Filing
The SEC organizes 8-K triggers into numbered items. The ones that move markets most often:
- Item 1.01 — Entry into a material definitive agreement (mergers, major contracts).
- Item 2.01 — Completion of an acquisition or disposition of assets.
- Item 2.02 — Results of operations and financial condition. This is the earnings-release item; nearly every quarterly earnings press release is furnished under 2.02.
- Item 5.02 — Departure or appointment of directors and principal officers. A sudden CEO or CFO exit filed under 5.02 is one of the most reliable red flags in disclosure.
- Item 7.01 / 8.01 — Regulation FD disclosures and "other events," the catch-all companies use for guidance updates and strategic announcements.
- Item 4.01 — Change in certifying accountant. An auditor resignation is a serious warning signal.
The four-business-day clock starts on the date of the triggering event, not the date of the press release. Some items (like 2.02 earnings) are "furnished" rather than "filed," a legal distinction that limits liability but not disclosure.
Worked Example: Tesla's Earnings 8-K
When TSLA reported Q2 2024 results on July 23, 2024, it furnished an 8-K under Item 2.02 the same day, attaching the earnings press release as Exhibit 99.1. The release showed automotive revenue of $19.9 billion and operating margin of 6.3%, down from 9.6% a year earlier. The stock dropped roughly 8% in after-hours trading within minutes of the filing hitting EDGAR. Traders watching the SEC feed saw the 8-K timestamp before most news wires had parsed the numbers. Earlier that year, Tesla also filed an 8-K under Item 5.07 disclosing shareholder votes at its annual meeting, including re-ratification of Elon Musk's 2018 pay package.
When Traders Use 8-Ks
Event-driven and special situation traders monitor the EDGAR 8-K feed in real time because it is the legally mandated first disclosure point for mergers, guidance changes, and management shake-ups. Merger-arbitrage desks read Item 1.01 filings to extract deal terms — price, break fees, closing conditions — before modeling the spread. Fundamental investors screen Item 4.01 and 5.02 filings as governance signals: a CFO departing mid-quarter or an auditor resigning precedes restatements often enough that many quant models short the signal automatically.
Limitations and Common Misconceptions
The four-day window creates an information gap: a company can sign a deal Monday and file Friday, and trading in between happens on rumors. Companies also exploit the "furnished vs. filed" distinction to soften liability on forward-looking statements. And an 8-K is only as complete as the company chooses to make it — the exhibit attachments carry the substance, so reading the cover page alone misses the deal.