A bank acceptance bill is a check cashed at maturity. You go to the bank to borrow money, and the bank draws you an acceptance bill, which can be used as cash, but the money is still in the bank. For derivative deposits, you have to pay interest, because bills of exchange are also money, which is counted as your loan. For derivative loans, what should you do with cash after you get the draft? You have to go to the bank to convert it into cash, but the conversion requires handling fees and discount fees in advance, so you get intermediary business income. That's it. If you understand, just adopt it. If in doubt, reply.