Uninsured Deposits and Liquid-Asset Coverage at US Banks, 2021–2026: A Critical Run Fraction With Fire-Sale Haircuts and an Exact Equity Condition

Using FDIC Call Report data for all US insured banks, I track uninsured deposits and the cash and securities available to meet their withdrawal at four dates: December 2021, December 2022, June 2023 and June 2026. Uninsured deposits were 44.4% of all deposits at the end of 2021, fell to 39.1% after the bank failures of spring 2023, and were back at 41.6% (8.69 trillion dollars) in June 2026. Cash plus securities covered 1.13 times uninsured deposits in aggregate at the end of 2021 and 0.99 times in June 2026; 1,628 banks holding 55.3% of bank assets had coverage below one. I define the critical run fraction, the largest share of uninsured deposits a bank can pay out by using cash and selling securities at a haircut h before either liquid assets or equity are exhausted, prove its closed form, and prove that the equity limit binds before the liquidity limit if and only if h exceeds the ratio of equity to securities. For June 2026 the median critical fraction is 1.16 at a 10% haircut, but 493 banks (holding 5.7% of assets) could not meet a run of half their uninsured deposits. Banks of 10 to 100 billion dollars are the most exposed, with a median critical fraction of 0.64. Uninsured-deposit shares are persistent: the rank correlation across banks between 2023 and 2026 is 0.85.