Futures were originally produced in forward contracts, which were produced in Chicago, USA. Located in the middle of the United States, near the Great Lakes, Chicago was the transportation hub and grain distribution center of the United States at that time. It has been found that when there is a good harvest, the price will drop sharply because of a large number of listings, but it will rise again in the season of food shortage. This brings inconvenience to food suppliers and food demanders. In order to ensure the supply of grain, people sign contracts to set the price and quantity before the grain goes on the market. This is a forward contract. However, because this kind of contract is very casual, the price and quantity of different contracts vary greatly, so it is difficult to circulate in the market. Later, people fixed the number of contracts and delivery methods, forming standardized forward contracts, that is, futures.