It should be a daily mark-to-market system, that is, a daily debt-free system and a daily settlement system. It means that after the end of each trading day, the settlement department of the exchange first calculates the settlement price of each futures contract on that day, and calculates the profit and loss of each member's transaction, so as to adjust the member's margin account, and the profit is credited to the account and the loss is credited to the account. If the credit limit in the margin account is lower than the margin requirement, the Exchange will notify the members to pay the additional margin within a certain time limit to reach the initial margin level, otherwise they will not be able to participate in the next trading day. The daily mark-to-market system generally includes two aspects: calculating floating profit and loss and calculating actual profit and loss.

China's domestic futures settlement system is a daily mark-to-market system, also known as the daily debt-free settlement system. In fact, in China, the exchange first managed members' funds according to the financial system of general enterprises, and adopted the monthly settlement system, without the awareness of controlling risks. Losses arising from daily transactions should be treated as floating losses. It can be proved that once the market continues to develop in an unfavorable direction for investors, the accumulated daily losses are so large that the margin balance is lower than the prescribed level, there will be the risk of being tied or even defaulting.

Stock index futures are marked to the market on a daily basis, that is, investors' profits and losses are settled after the settlement on the same day, and positions' profits and losses calculated at the settlement price on the same day are increased or decreased. It plays an important role in controlling the risk of stock index futures market and maintaining the normal operation of the market.