What Is GAAP?
Generally Accepted Accounting Principles, or GAAP, is the common rulebook governing how companies in the United States measure and report their financial results. It covers everything from when revenue can be recognized to how leases, inventory, and goodwill must be treated.
The rules are written primarily by the Financial Accounting Standards Board (FASB), and the SEC requires all US public companies to file GAAP-compliant financial statements. Without a shared standard, comparing one company's numbers to another's would be close to meaningless.
GAAP vs. IFRS
Most of the world outside the US uses International Financial Reporting Standards (IFRS), set by the IASB. GAAP tends to be more rules-based with detailed prescriptions, while IFRS is more principles-based and leaves more room for judgment.
Concrete differences matter in practice: GAAP permits LIFO inventory costing while IFRS bans it, and the two frameworks differ on items like development cost capitalization and asset revaluations. Analysts comparing a US company to a European peer need to be alert to these gaps.
GAAP vs. Non-GAAP Metrics
Companies frequently report non-GAAP or adjusted figures, such as adjusted EBITDA or adjusted EPS, which strip out items management deems non-recurring, like restructuring charges or stock-based compensation. These can be informative, but they are also where companies flatter their results, so the SEC requires reconciliation back to the nearest GAAP measure.
A useful habit is to compare a company's GAAP net income to its adjusted figures over several years; a persistently wide gap is a red flag worth investigating.
Why It Matters
GAAP is the foundation of trust in capital markets: investors, lenders, and acquirers all rely on the comparability it provides when pricing securities and deals. Every 10-K and 10-Q you will ever read is built on these standards.
For aspiring bankers and analysts, fluency in GAAP concepts like revenue recognition and the matching principle is assumed knowledge in interviews and on the job.
