Stock price index futures (SPIF), full name of stock price index futures, also known as stock price index futures and futures index, refers to standardized futures contracts with stock price index as the subject matter. The two sides agreed that on a specific date in the future, the underlying index can be bought and sold according to the size of the stock price index determined in advance, and the difference will be settled in cash after the expiration. As a kind of futures trading, stock index futures trading is basically the same as ordinary commodity futures trading. Stock index is a kind of futures. Futures can be roughly divided into two categories, commodity futures and financial futures.