Basel III is the international regulatory framework, developed by the Basel Committee on Banking Supervision following the 2008 financial crisis, that sets minimum capital, leverage, and liquidity requirements banks must hold to absorb losses and survive periods of market stress.
Why It Matters
Basel III's capital and liquidity rules directly shape how much banks can lend, what kinds of assets they favor, and how they price risk — it's the regulatory backbone behind nearly every large bank's capital planning, and the ongoing U.S. implementation debate (the 'Basel III Endgame' proposals) has been one of the most consequential regulatory fights in banking over the past several years.
How It Works in Practice
- 1Common Equity Tier 1 (CET1) capital ratio: requires banks to hold a minimum ratio of high-quality capital against risk-weighted assets
- 2Leverage ratio: a non-risk-weighted backstop measure, capital against total (unweighted) exposure, meant to catch risks that risk-weighting might understate
- 3Liquidity Coverage Ratio (LCR): requires enough high-quality liquid assets to survive a 30-day stress scenario
- 4Net Stable Funding Ratio (NSFR): requires stable funding sources relative to the liquidity profile of a bank's assets over a one-year horizon
Common Pitfalls
Basel III sets minimums, but national regulators frequently layer additional buffers and requirements on top (stress capital buffers, G-SIB surcharges), so "Basel III compliant" doesn't fully describe any specific large bank's actual requirement
Risk-weighted asset calculations depend on models banks build themselves (under the advanced approaches), which has historically produced meaningful variation in reported capital ratios across banks with genuinely similar risk profiles
Implementation timelines and specifics differ by jurisdiction, and the U.S. "Endgame" proposals have been repeatedly revised, so current requirements should always be verified against the latest final rule, not the original 2017 framework