The 10-K is the primary source document for fundamental work. Unlike the glossy annual report, it is written for regulators and lawyers, which makes it duller and considerably more honest.
The order that rewards a first read is: the business description, then risk-factors, then managements-discussion-and-analysis, then the statements, then the footnotes. Filing deadlines run 60 to 90 days after year end depending on company size.
Example: Northwind Tools files a 214-page 10-K in February. The segment note is where the Cloud arm's 78% gross margin becomes visible, since the income statement shows only the consolidated 44%.
Related: form-10-q, risk-factors, managements-discussion-and-analysis, footnotes, edgar