There are four contracts in stock index futures, usually the main contract of the current month, three contracts for the next month and two quarterly contracts (3.6.9. 12). For example, in March, the assistant contract is if 1503, then the other three contracts are if 1504, if 1506 and if 1509. The delivery date of the main contract is the third Friday of the current month (postponed in case of legal holidays). If we look at the timetable, the March contract expires on March 20th, so generally from March 18, the funds will be gradually transferred to if 1504. By March 23rd (2 122 is the weekend), you will see that the main contract is if 1504.
The full name of stock index futures is the Shanghai and Shenzhen 300 Index, and the top 300 heavyweights in Shanghai and Shenzhen stock markets are selected. Then you will know that the stock market has an impact on the stock index.