Stock index futures refer to investment instruments listed on the stock exchange, and their prices are affected by complex market factors. This investment tool is very important for the stock market because it can predict the trend of the stock market. The following are three reasons why stock index futures affect the stock market.

1. The price of stock index futures affects investors' mood: the price fluctuation of stock index futures will reflect the market's expectation of future stock price changes. If the price of stock index futures rises, it means that most investors expect the stock market to go higher, otherwise it reflects that the market expects the stock market to go lower. This expectation will directly affect the mood of investors, thus triggering the action of buying or selling stocks.

2. The trading volume of stock index futures indicates the liquidity demand of the stock market: the trading volume of stock index futures will directly reflect the liquidity demand of the stock market. If the stock price fluctuates greatly, the trading volume will often increase greatly. This trend will make investors notice that the liquidity demand in the stock market has increased, thus reflecting the future investment opportunities in the stock market.

3. Stock index futures can guide the flow of funds to the stock market: the impact of stock index futures on the stock market is related to its price level. When the price of stock index futures rises and shows a rebound trend, a large number of investment institutions and funds flow to the stock market for investment. In addition, influenced by investors' mentality, the trend of stock index futures can also guide the choice of investment direction of funds in the stock market.

To sum up, stock index futures have a certain impact on the stock market. For investors, understanding and observing it is helpful to quickly adjust investment strategies in a short period of time in order to obtain better return on investment.