★ The impact of the introduction of stock index futures on the stock market: First, the short-selling mechanism of margin financing and securities lending is mainly aimed at a single stock, while the short-selling mechanism of stock index futures is mainly aimed at the market index. The significance of the introduction of stock index futures is that investors can make profits according to the accurate judgment of market trends. Therefore, the phenomenon that investors underestimate the market and value individual stocks will be improved to some extent in the future. Second, stock index futures have the characteristics of low transaction cost, high leverage ratio and fast instruction execution. Therefore, the initial launch will attract a large number of speculators to enter the stock index futures market, thus reducing the liquidity of the spot market. However, in the long run, the hedging and arbitrage functions of stock index futures can significantly reduce the systemic risks in the spot market, thus helping to attract a large number of long-term funds with low risks to continue to enter, and greatly improving the liquidity and scale of the stock market. Third: Third, in the initial stage of the full circulation market construction after the share-trading reform, the stock market not only faces the continuous expansion of the scale of lifting the ban on non-tradable shares, the continuous acceleration of refinancing and the expansion of new shares, and the surge of mergers and acquisitions of listed companies, but also faces the short-term market impact brought by various policy changes in the process of market system construction and product innovation. At this time, the hedging function of stock index futures will enable investors to effectively guard against the systemic risks brought by unexpected events, thus achieving the stability of market psychological expectations and ensuring the reform and smooth transition of the market. Fourth, because the profit center of hedgers is in the spot market, while the profit center of speculators is in the stock index futures market, that is, speculators mainly use the influence of the spot market on the futures market to obtain income. Therefore, this has caused speculators to gradually shift to the futures market, reducing excessive speculation in the spot market. However, due to the influence of the futures market on the stock market, the volatility of the stock market tends to increase. At the same time, the stock index futures market also has a certain substitution and containment effect on the speculation of warrants. Fifth, the market arbitrage function of stock index futures accelerates the information transmission between futures, improves the liquidity of spot market and improves the pricing mechanism of stock market. In particular, stock index futures can effectively reduce the operating frequency of institutional investors on blue-chip stocks, and the implementation of margin system improves the efficiency of capital utilization, and at the same time doubles the risks and benefits of investors. Sixth, securities short selling needs to borrow securities, which must be borrowed through brokers, so the trading volume is small; Short-selling stock index futures is convenient and large. At the same time, short selling through securities lending can accurately suppress individual stock prices, while stock index futures are mainly used to avoid systematic hedging of market indexes, and the transaction cost of stock index futures is only one tenth of that of stock trading. Considering that the systemic risks in the US and UK markets are 26.8% and 32.7% respectively, while the China market is as high as 65.7%, the introduction of stock index futures will help to avoid the systemic risks in China's A-share market and lock in the downside risks by selling stock index futures, thus avoiding market panic and enhancing the attractiveness of the A-share market to long-term funds. Seventh, in order to prevent the risk that the market may be manipulated after the introduction of stock index futures, the listing of super-large-cap stocks in China A-share market is accelerating to establish a stock index that is not easily manipulated.