10-K, 10-Q, and 8-K: the SEC filings behind company financials

What 10-K, 10-Q, and 8-K filings are

Q4 Result = Full-Year Total (10-K) - (Q1 (10-Q) + Q2 (10-Q) + Q3 (10-Q))

Public companies listed in the United States must file regular disclosure reports with the Securities and Exchange Commission (SEC) under the Securities Exchange Act of 1934. Three filings form the backbone of corporate financial reporting for domestic issuers: Form 10-K, Form 10-Q, and Form 8-K. Form 10-K is the comprehensive annual report containing audited financial statements, detailed footnote disclosures, business descriptions, and risk factors. Form 10-Q is the shorter quarterly report containing unaudited financial statements and management updates for each of the first three quarters of the fiscal year.

Form 8-K serves a different purpose as a current report that companies file between periodic reports whenever a material corporate event occurs. Common triggers for an 8-K include quarterly earnings releases furnished under Item 2.02, leadership changes, mergers or acquisitions, new debt agreements, and auditor changes. Foreign private issuers that trade on US exchanges follow a parallel framework, filing annual reports on Form 20-F (or Form 40-F for eligible Canadian companies) and submitting interim updates on Form 6-K.

Because the SEC requires Form 10-Q only for the first three fiscal quarters, companies do not file a separate fourth-quarter 10-Q. Instead, fourth-quarter activity is incorporated into the full-year audited statements inside the annual Form 10-K. To isolate standalone fourth-quarter revenue, expenses, or cash flows, analysts subtract the sum of the first three quarters reported in the 10-Q filings from the full-year total reported in the 10-K, or calculate trailing twelve months (TTM) figures by adding the latest 10-Q cumulative period to the prior 10-K and subtracting the prior-year comparable 10-Q period.

Worked example: deriving Q4 and trailing twelve-month figures

Consider a hypothetical manufacturing company, Apex Industrial Corp., whose fiscal year ends on December 31. In its first three Form 10-Q filings for the year, Apex reports quarterly revenue of $200 million in Q1, $220 million in Q2, and $230 million in Q3, bringing nine-month cumulative revenue to $650 million. Two months after year-end, Apex files its annual Form 10-K reporting audited full-year revenue of $900 million and full-year net income of $90 million. Although Apex does not file a Q4 10-Q, subtracting the $650 million nine-month revenue total from the $900 million full-year figure reveals fourth-quarter revenue of $250 million.

The same relationship applies when calculating trailing twelve-month (TTM) figures mid-year as new 10-Q filings arrive. Suppose that in the following fiscal year, Apex files its Q1 Form 10-Q showing revenue of $230 million for the three months ended March 31, compared with $200 million in Q1 of the prior year. To calculate TTM revenue after Q1, an investor starts with the prior 10-K full-year revenue of $900 million, adds the new Q1 10-Q revenue of $230 million, and subtracts the prior-year Q1 10-Q revenue of $200 million. This calculation yields TTM revenue of $930 million, reflecting the four most recent completed quarters of operations.

Before the 10-K or 10-Q is formally filed, Apex typically announces its quarterly results through a press release attached to a Form 8-K under Item 2.02. That 8-K provides preliminary summary numbers, such as the $250 million in fourth-quarter revenue, several days or weeks before the complete 10-K is submitted. Once the 10-K or 10-Q is filed, investors verify those preliminary figures against the complete financial statements and footnotes.

How to interpret filings: deadlines, structure, and industry differences

SEC filing deadlines depend on a company's public float, which divides domestic issuers into three tiers: large accelerated filers (public float of $700 million or more), accelerated filers ($75 million to under $700 million), and non-accelerated filers (under $75 million). For Form 10-K, large accelerated filers must file within 60 days after fiscal year-end, accelerated filers within 75 days, and non-accelerated filers within 90 days. For Form 10-Q, large accelerated and accelerated filers have 40 days after quarter-end, while non-accelerated filers have 45 days. Form 8-K generally must be filed within four business days of the triggering corporate event.

Within a 10-K, the most heavily analyzed sections live in Part I and Part II. Item 1 and Item 1A cover the business model and risk factors, while Item 7 contains Management's Discussion and Analysis of Financial Condition and Results of Operations (MD&A), where executives explain drivers of revenue, margins, and liquidity. Item 8 houses the audited balance sheet, income statement, cash flow statement, statement of stockholders' equity, and the accompanying footnotes. A 10-Q follows a condensed structure in Part I, featuring unaudited financial statements in Item 1 and quarterly MD&A in Item 2.

How investors interpret these disclosures varies significantly by industry because accounting rules and operating metrics differ across sectors. For commercial banks, the 10-K and 10-Q footnotes and MD&A center on net interest margin, loan loss provisions, deposit composition, and regulatory capital ratios rather than inventory or gross margin. For software companies, analysts focus on deferred revenue on the balance sheet and remaining performance obligations disclosed in the revenue recognition footnotes. For retailers and manufacturers, segment breakdowns, inventory valuation methods, and lease commitments in the footnotes carry the greatest weight.

Limitations and common mistakes when using SEC filings

One frequent mistake is confusing preliminary figures in an Item 2.02 Form 8-K earnings release with audited or GAAP-compliant figures in a 10-K or 10-Q. Earnings releases attached to an 8-K often emphasize non-GAAP metrics, such as adjusted EBITDA or non-GAAP net income, which exclude stock-based compensation, restructuring charges, or amortization. While companies must reconcile non-GAAP numbers to the closest GAAP measure, the 8-K press release rarely includes complete footnote disclosures or full cash flow and balance sheet details. Relying solely on the 8-K can cause investors to miss off-balance-sheet obligations, customer concentration disclosures, or changes in accounting estimates that appear only in the 10-Q or 10-K footnotes.

Another common error occurs when comparing quarterly 10-Q results without accounting for seasonality or fiscal calendar differences. Because 10-Q statements are unaudited, they are subject to year-end audit adjustments and lack the full schedule of annual tax, pension, and stock compensation disclosures found in the 10-K. Furthermore, some retailers use a 52-53 week fiscal calendar where every fifth or sixth year includes an extra fourth-quarter week in the 10-K, which can distort year-over-year growth comparisons if not adjusted.

Investors also run into pitfalls when analyzing restatements or accounting changes across historical periods. When a company restates prior financial statements or adopts a new accounting standard retrospectively, the updated comparative numbers appear in subsequent 10-Q or 10-K filings rather than altering the original historical filing text. Checking Item 4.02 on Form 8-K, which flags non-reliance on previously issued financial statements, helps investors identify when historical filings have been superseded.

How StockData calculates it

All of StockData's financial statements come directly from the XBRL data embedded in these official SEC filings. For US domestic companies, annual figures are extracted from the audited Form 10-K (filed 60 to 90 days after fiscal year-end depending on filer size), and quarterly figures for Q1 through Q3 come from the unaudited Form 10-Q. For foreign private issuers listed in the United States, StockData uses annual filings on Form 20-F or Form 40-F and interim reports on Form 6-K.

Every financial figure displayed on StockData links directly to the specific SEC filing it came from, allowing you to verify the underlying XBRL tag and footnote context at the source. In addition to standardized financial statements, StockData tracks Form 8-K current reports for material events, including quarterly earnings releases furnished under Item 2.02. You can browse these earnings releases alongside investor presentations and periodic reports on StockData's /research page.

Common questions