Futures is a debt-free day settlement system, and the profit of opening and closing positions on the same day is a normal algorithm, that is, the price difference. If it is a complicated overnight, the purchase price and settlement price of the day will be calculated, and the price of the next day and the settlement price of the previous day will be calculated as the difference. The margin of the transaction is fixed, but if you close the position forcibly or cross-close the position, the difference will be deducted from your margin, or you have to ask for it separately.