Opening equity can be understood as the account equity before the futures trading day, which is mainly used to facilitate futures settlement. The beginning of accounting can be understood as the end of the period, and the end of the period MINUS the beginning (in the case of no account transfer) is the profit and loss of the current day or period.

In the futures market, traders can pay a small amount of money according to a certain proportion of the price of futures contracts as financial guarantee for the performance of futures contracts and participate in the trading of futures contracts. This kind of money is the futures margin.

In China, futures margin (hereinafter referred to as margin) can be divided into two categories according to its nature and function: settlement reserve and trading margin.

Settlement reserve is generally paid by member units to the exchange according to fixed standards, and prepared in advance for transaction settlement. Settlement reserve refers to the funds prepared in advance by members in the special settlement account of the exchange for transaction settlement, which is the deposit not occupied by the contract. The minimum balance of the settlement reserve shall be determined by the exchange.

Trading margin refers to the actual deposit paid by member units or customers for holding futures contracts in futures trading. Divided into initial margin and additional margin: initial margin and additional margin.