In a word, stock index futures originated from the stock market, but they are essentially different from the stock market. Based on the stock market, it has a negative effect on the stock market, especially on the short-term trend of the stock market, which has a "leading effect".
Extended data
In commodity futures trading, individual investors have no right to hold positions before the final delivery date. If you don't close your position by yourself, your position will be forcibly closed by the exchange, and all the consequences will be borne by the investors themselves. Only the spot enterprises that have applied to the exchange for hedging qualification and obtained approval can hold their positions until the final delivery date and enter the delivery procedure, because they have hedging needs and qualifications.
The delivery place is the delivery warehouse designated by each futures exchange. The delivery method includes that some futures contracts agree on the price at the trading time and complete the delivery off-site; Or after entering the delivery time.
Baidu Encyclopedia-Stock Index Futures Delivery Date