The main income of banks is the spread between loans and deposits, but all the deposits absorbed cannot be turned into loans, and there must be position funds to ensure daily payment and corporate settlement. The regulatory loan-to-deposit ratio stipulated by the Banking Regulatory Bureau is 75%, that is, loans cannot exceed 75% of deposits. Therefore, banks must make surplus loans from deposits, otherwise, if there are too many loans, the risks will be even greater, and even vicious financial events such as bank runs will be triggered.