 Throughout the course of a day, banks will transfer money to each other, to foreign banks, to large clients, and other counterparties on behalf of clients or on their own account.At the end of each working day, a bank may have a surplus or shortage of funds (or a shortage or excess reserves in fractional reserve banking).Banks that have surplus funds or excess reserves may lend them (often at a multiple of their legal reserve ratio, if any) or deposit them with other banks, who borrow from them.