The essence of futures is to sign a trading contract. Futures contracts are publicly traded (signed) in futures exchanges, and trading refers to the value of futures contracts themselves. For example, soybeans are now 3,700 yuan/ton, and each batch is 10 ton, worth 37,000 yuan. According to the margin calculation of 10%, you need a margin of 3,700 yuan to buy and sell a soybean futures contract, and the buying and selling price is obtained through open bidding.