Tracing Bank Runs in Real Time (Revised June 2026)

Using high-frequency interbank payments data to trace deposit flows in March 2023, we identify twenty-two bank runs — ten times the two bank failures. Runs are driven by relatively few but large depositors fleeing to the largest banks and out of the banking system altogether. Run banks' characteristics highlight a role for both fundamental and non-fundamental drivers of runs, including solvency, liquidity, deposit concentration and coordination through public signals. Surviving banks bridge the deposit reallocation by borrowing from Federal Home Loan Banks and the discount window, eventually replacing lost uninsured deposits with insured deposits at higher rates in the medium term.