The Liquidity Coverage Ratio

Banks that were solvent on paper in 2008 still failed, because solvency and liquidity are different problems: a bank can own more assets than liabilities and still collapse if it can't turn those assets into cash fast enough when depositors and lenders all want out at once. The Liquidity Coverage Ratio, introduced under Basel III, was built directly in response — it forces banks to prove, with a specific number, that they could survive a month of severe funding stress using only assets they could actually sell quickly.

The formula

$$LCR = \frac{\text{High-Quality Liquid Assets}}{\text{Net Cash Outflows over 30 days}} \geq 100\%$$

In words: high-quality liquid assets (HQLA) are things like central bank reserves and highly rated government bonds — assets that stay sellable even in a crisis. Net cash outflows are modeled under a standardized stress scenario: a chunk of deposits fleeing, credit lines being drawn down, wholesale funding not rolling over. A ratio at or above 100% means the bank's liquid buffer covers the stress case; below 100% means it would run out of ready cash before the month is up.

Worked example

A bank holds $130 billion of HQLA — mostly central bank deposits and government bonds. Regulators require it to model net cash outflows under a stress scenario: 10% of retail deposits leaving ($40 billion outflow), half of its committed credit lines being drawn ($50 billion outflow), partially offset by $20 billion of contractual inflows from maturing loans, giving net outflows of $70 billion.

$$LCR = \frac{\$130\text{bn}}{\$70\text{bn}} \approx 186\%$$

The bank is comfortably above the 100% minimum, meaning it holds nearly twice the liquid assets needed to survive the modeled 30-day stress scenario. A bank showing an LCR of 95% would be in breach and subject to regulatory intervention — typically a requirement to shrink lending, raise more stable funding, or grow its HQLA buffer.

What this means in practice

The LCR is one of the main reasons banks now hold much larger reserves of government bonds and central bank deposits than they did before 2008, even though those assets earn relatively little — the return given up is treated as the cost of the insurance against a funding freeze. It also shapes bank behavior in ways beyond the letter of the rule: banks manage their balance sheets to keep the ratio comfortably above 100% at all times, not just at reporting dates, because a bank publicly reported as near the minimum invites exactly the depositor anxiety the rule was designed to prevent.