Chicago Board of Trade (CBOT) wheat futures contracts have a trading unit of 5,000 bushels, with the minimum change price of US cents per bushel 1/4 (US$ 0/2.50 per contract), and the highest price per bushel on the previous trading day is not higher or lower than 20 cents (US$ 0/000 per contract). The trading hours of spot month unlimited contract month 7, 9, 12, 3 and 5 are from 9: 30 am to afternoon 1: 15 (Chicago time), and the closing time of the last trading day of the expired contract is the seventh trading day from the last trading day of the delivery month at noon that day. The delivery grades are Soft Red Wheat No.2, Hard Red Winter Wheat No.2, Black North Spring Wheat No.2 and 1 North Spring Wheat. The price difference of substitute varieties shall be stipulated by the exchange. The gold trading unit of the standard gold futures contract of Shanghai Futures Exchange is 1000g/ lot. The quotation unit is RMB/gram. The minimum fluctuation price is 0.0 1 yuan/day, and the maximum fluctuation limit of the price shall not exceed 5% of the settlement price of the previous trading day. The delivery month of the contract is1-65438+February, and the trading hours are 9: 00 am-65438+0:30 pm+0: 30 pm (the delivery month of the contract on the last trading day is 15), so the grade gold content produced by qualified suppliers or refineries recognized by London Gold and Silver Market Association (LBMA) is not high.