The Margin System, also known as the margin system, refers to the system stipulated by the clearing house that the buyer or seller who makes a futures transaction should pay the performance bond. In futures trading, any trader must pay a certain proportion (usually 5% ~ 10%) of the price of the futures contract he buys and sells as the fund guarantee for his performance of the futures contract, and then he can participate in the futures contract trading and decide whether to add funds according to the price. This system is the deposit system, and the money paid is the deposit.