The 10-K is the single most important document a U.S. public company files. It is the annual report — audited, dated, signed by the CEO and CFO, and submitted to the SEC within 60 to 90 days of fiscal year-end depending on the company's size. Every headline number you see in financial news about a U.S. company — revenue, margins, debt load, segment performance — ultimately comes from a 10-K (or a quarterly 10-Q).

Where it lives

Every public company's filings are free to download from the SEC's EDGAR system. The canonical entry point is the company's EDGAR profile, reached via its CIK (Central Index Key). For example:

• Alphabet Inc.: CIK 0001652044
• Apple Inc.: CIK 0000320193

Filings come in several formats. For reading, the 10-K/A (amended) or 10-K HTML is human-friendly. For parsing, the XBRL (Inline or standalone) attachment is structured data — it's what powers the financial statements on this site.

The skeleton

Every 10-K is organized around four parts. The SEC's Regulation S-K fixes the structure, so whether you open a filing from 2005 or 2025, the sections live in roughly the same order.

For most analytical work, Part I Item 1, Part II Item 7, and Part II Item 8 are where you spend your time. Everything else is context.

What to read first

Experienced analysts have a standard reading order that pulls signal out fastest:

• Item 1 — Business. Start here. A well-written Item 1 tells you what the company does, how it makes money, and which segments matter. Pay attention to how the company defines its segments — segment boundaries drive every subsequent disclosure.
• Item 7 — MD&A. Management's Discussion & Analysis is where the CFO explains the year in plain English. Look for what management emphasizes, what it glosses over, and — most importantly — what it changed from last year's filing. Year-over-year language drift in the MD&A often signals a shift in strategy or a problem being soft-pedaled.
• Item 8 — Financial Statements. The four primary statements (income statement, balance sheet, cash flow, shareholders' equity) live here, followed by the notes. The notes are where disclosures actually happen: segment breakdowns, lease commitments, off-balance-sheet arrangements, tax reconciliation, stock-based compensation mechanics, acquisition purchase-price allocation, revenue-recognition policy.
• Item 1A — Risk Factors. A long, hedged, lawyerly document. Skim it, but read the first three to five risks carefully — companies generally order them by perceived materiality.

The numbers you'll encounter

The financial statements in a 10-K are presented at three levels of detail:

1. Face of the statements — one-page summaries of the income statement, balance sheet, cash flow, and shareholders' equity. These are what most people call "the financials."
2. Notes to the financials — pages of disclosures that explain the face. Segment results, geographic revenue, lease schedules, pension obligations, deferred tax assets, related-party transactions — the notes are where the real information density lives.
3. Supplementary schedules — exhibits at the end of the filing, mostly used by regulators and auditors.

When a chart on this site cites a 10-K number, it's almost always pulled from the face of the statements; any finer-grained breakdown (e.g. segment revenue) comes from the notes.

A worked example

Take a look at Alphabet's financials. Every line item on that page was parsed from an XBRL attachment of a 10-K or 10-Q filing. The chart of accounts that normalizes those line items across years is versioned in this repository — drift in a tag mapping would show up as a visible step-change in a time series, not a silent correction.

The difference between good and bad financial analysis is not which spreadsheet you build — it is whether you read the filing first. Numbers without context are always misleading.

Where to go next

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