Stock index futures is a new tradable financial product relying on the A-share market, which has a causal relationship with A-shares. However, it is partial and personalized, which will not affect the operation and development of A-share entity companies, and has nothing to do with A-share performance. It only relies on the trend change of A shares, or uses funds to promote the trend to make a profit, which makes it produce unexpected changes.

The full name of stock index futures (SPIF) is stock index futures, which can also be called stock index futures and futures index. It refers to the standardized futures contract with the stock price index as the subject matter. The two parties agree to buy and sell the underlying index according to the size of the stock price index determined in advance at a future date, and settle the difference in cash after the expiration. As a type of futures trading, stock index futures trading has basically the same characteristics and processes as ordinary commodity futures trading. Stock index futures are a kind of futures, which can be roughly divided into two categories, commodity futures and financial futures.

The official name of A shares is RMB common stock. Common shares issued by companies in China for domestic institutions, organizations or individuals (excluding investors from Taiwan, Hong Kong and Macao) to subscribe and trade in RMB. A shares are not physical shares. Electronic recording, paperless, implementation of "T+ 1" delivery system, price limit (10%). The participating investors are Chinese mainland institutions or individuals. The stocks of listed companies in China are divided into A shares, B shares, H shares, N shares and S shares. This distinction mainly depends on the place where the stock is listed and the investors it faces.