Futures trading in a fair, open and just situation, futures trading must be conducted in an open and centralized manner on the exchange in accordance with laws and regulations, and cannot be conducted over the counter. In addition to national laws, industry and exchange rules, futures trading mainly depends on the margin system to ensure maturity. The direct object of futures trading is futures contracts, not how many contracts to buy or sell. Futures trading is conducted in an open and fair manner. One-on-one negotiation (or private hedging) is considered illegal. From these, we can see the "three public" policies of futures. To be exact, the subject matter of futures is spot, and the futures price tends to spot price when it is close to delivery, and finally it is traded at spot price. It can be said that futures and spot are complementary.