Every US public company produces a steady stream of SEC filings, but three of them carry most of the information an investor needs: the 10-K, the 10-Q, and the 8-K. They are not interchangeable. Each answers a different question and arrives on a different schedule. Knowing which is which saves you from reading the wrong document at the wrong time.
| 10-K | 10-Q | 8-K | |
|---|---|---|---|
| What it is | Annual report | Quarterly report | Current report |
| Frequency | Once a year | 3 times a year | As events occur |
| Financials | Audited | Unaudited | Usually none |
| Deadline | 60 to 90 days after year-end | 40 to 45 days after quarter-end | 4 business days after the event |
| Length | 100+ pages | 30 to 60 pages | 1 to a few pages |
| Read it for | The full picture | What changed this quarter | What just happened |
The 10-K: the full picture, once a year
The 10-K is the annual report a company files with the SEC. It is the most complete single document about a business you will find anywhere: audited financial statements, a full description of the business, risk factors, and management's discussion of the year. Because the numbers are audited, the 10-K is the version of the financials you can most rely on.
The tradeoff is timing. A 10-K is due 60 days after the fiscal year ends for the largest companies, and 75 or 90 days for smaller ones, so it arrives with a lag and covers a full year at once. Read it when you are getting to know a company or doing a thorough annual review. Our guide to reading a 10-K covers the five sections that matter most.
The 10-Q: what changed this quarter
The 10-Q is the quarterly update. Companies file three of them per year, one after each of the first three quarters, and the fourth quarter is folded into the annual 10-K. It is shorter than a 10-K and its financial statements are unaudited, meaning they are reviewed but not subjected to the full audit the annual figures get.
The 10-Q exists to keep the picture current between annual reports. Its deadline is tighter, 40 days after quarter-end for larger filers and 45 for smaller ones. The most useful part is the management discussion (MD&A), which explains what moved during the quarter and how the current period compares to the same quarter a year earlier. When you already follow a company, the 10-Q is often the filing you read most.
The 8-K: what just happened
The 8-K is the real-time channel. Rather than following a calendar, it is filed whenever a specific material event occurs, generally within four business days. Earnings releases, executive departures, acquisitions, bankruptcies, and other significant developments all arrive as 8-Ks. A single company might file dozens in a year or only a handful.
Each 8-K is tagged with item codes that tell you what kind of event it reports before you read a word. An 8-K under Item 2.02 is an earnings release; one under Item 5.02 is a management change. Our guide to 8-K item codes breaks down which events move markets and which are routine.
How they fit together
Think of the three as different time horizons on the same business. The 10-K is the annual snapshot, deep and audited but slow. The 10-Q keeps that snapshot current each quarter. The 8-K fills the gaps in between, flagging events the moment they happen. A complete view of a company uses all three: the 10-K for depth, the 10-Q for the trend, and the 8-K for the news.
SignalX indexes every one of these filings from SEC EDGAR as it is published and generates AI summaries of the sections that carry signal. Start from a company you follow, for example Apple, to see its 10-K, 10-Q, and 8-K filings side by side.