As of the end of 2022, Silicon Valley Bank (SVB) had a PCA designation of Well Capitalized, determined by all of the PCA financial ratios SVB reported $14.5 billion of common equity capital on its December 2022 Call Report balance sheet This "Well Capitalized" bank was taken over by the FDIC on March 10, as the bank could not handle a sudden outflow of $46 billion of deposits, and thus the bank failed. In reality the balance sheet was quite fragile. No healthy bank is ever going to have a run on the bank and thus fail What reasons (there's more than one) were behind this bank's fragility, and thus caused the bank to be a sitting duck for a loss of confidence