What Is an 8-K Filing?
By InsiderAlpha · Published
Written from SEC primary filings, with every rule cited inline. Editorial standards.
A Form 8-K ("current report") is how a U.S. public company tells the market that something material just happened - generally within four business days of the event. Unlike the scheduled 10-K and 10-Q, an 8-K can drop at any moment, which is why it is the filing most likely to move a stock price the day it appears.
Common 8-K items and what they mean
- Item 1.01 - Entry into a material agreement (contracts, partnerships, licensing deals).
- Item 1.03 - Bankruptcy or receivership.
- Item 2.01 - Completion of an acquisition or disposition.
- Item 2.02 - Earnings (results of operations). Most earnings press releases arrive as an 8-K first.
- Item 3.01 - Delisting notice from the exchange.
- Item 5.02 - Executive changes: CEO/CFO departures, appointments, and board changes. One of the most price-sensitive items.
- Item 7.01 / 8.01 - Regulation FD and "other events" - the catch-alls for everything from clinical-trial results to major contract wins.
- Item 1.05 - Material cybersecurity incidents (required since December 2023).
This is the short list. For every item number - including the rare, high-impact ones like restatements (4.02) and changes in control (5.01) - plus real data on how often each appears, see the full 8-K item reference.
Why traders watch 8-Ks
An 8-K is a catalyst: it changes the information set on a name immediately. The classic pattern is an 8-K landing while insiders are already positioned - an executive-change 8-K after a CEO purchase, or a contract-win 8-K following a cluster buy, retells the insider story with the missing context. InsiderAlpha surfaces every 8-K as it is filed, with a link straight to the original document, and cross-references it against insider buying in the same name over the preceding six weeks - see today's 8-K filings. Reading the filing itself is your job, not ours: we point you at it and tell you who was buying beforehand.
8-K vs Form 4
The two filings answer complementary questions: Form 4 shows what insiders did with their own money; the 8-K shows what the company says is happening. When the two agree - insiders buying ahead of a positive catalyst - the combined signal is much stronger than either alone.
This article is informational and is not investment advice.