Futures and spot are linked by due delivery. By the delivery date, the futures price will converge with the spot price, otherwise there will be arbitrage space. Participating in the price is a certain standard of spot goods. First of all, it is necessary to deposit the spot in the delivery warehouse designated by the exchange to obtain the standard warehouse receipt of futures. The standard warehouse receipt is delivered in the exchange, and the buyer can pick up the goods in the delivery warehouse after getting the standard warehouse receipt.