Form 8-K
An SEC filing that publicly traded companies must submit to report significant events that shareholders need to know about promptly.
What is Form 8-K?
Form 8-K (also called a 'current report') is an SEC filing that U.S. public companies must submit to disclose material events that could affect investors' decisions. Companies are generally required to file an 8-K within four business days of the triggering event. Required disclosures include: entry into or termination of a material definitive agreement; bankruptcy or receivership; completion of an acquisition or disposition; results of operations and financial condition (earnings releases); changes in directors or principal officers; amendments to the articles of incorporation or bylaws; departure or appointment of the CEO/CFO; auditor changes; and restatements of financial results. The 8-K provides investors with timely transparency between annual (10-K) and quarterly (10-Q) reports. Investors, analysts, and algorithms monitor the SEC's EDGAR system for 8-K filings in real time because they frequently move stock prices significantly.
Example
On August 24, 2011, Apple filed an 8-K disclosing that Steve Jobs had resigned as CEO, effective immediately. The filing was made after market close and triggered a 5% drop in Apple's stock price when markets opened the next day. Because the CEO departure was a material event affecting investors' assessment of the company's future prospects, it required immediate 8-K disclosure — consistent with Regulation FD rules against selective disclosure.
Source: SEC — Form 8-K Requirements