Briefly describe the elements of futures contracts.
A: Futures contracts usually include four basic elements. (1) The underlying product refers to the product specified for delivery in the futures contract. (2) Transaction price refers to the way in which futures contracts generally stipulate price changes during the transaction, including: quotation unit, minimum price change unit and daily price change limit. (3) the number of transactions, that is, the futures exchange clearly stipulates the number contained in each futures contract, also known as the trading unit. When the parties conduct a transaction, the transaction quantity shall be calculated according to the sales contract quantity. (4) Closing period, that is, the futures contract should also determine the delivery month and delivery date according to the supply and demand characteristics of the transaction target.