Answer:
ROA = return on assets = income / average total assets
Banks are in the business of receiving money (liabilities) and lending money (assets), and their profit is made for the difference that they pay for deposits and the money that they charge for loans. That is why assets and liabilities are very large for banks, while equity tends to be very small compared to liabilities.
For example, the average debt to equity ratio for banks range from 2 to 3, depending on whether they are commercial or investment banks. Assuming a debt to equity ratio of 3, liabilities represent 75% of the banks assets while equity represents only 25%. That is why a small ROA can represent a large ROE (return on equity).
