Mark-to-market system means that after each trading day, the futures company calculates the profit and loss of each transaction of each customer according to the settlement price of each futures contract on the day of the exchange, so as to adjust the customer's margin account, record the profit into the customer's margin account, and deduct the loss from the customer's margin account. If the equity amount in the customer's account is lower than the margin level, the futures company will notify the customer to pay the recovery margin within a time limit. Ensure that the rights and interests reach the margin level.