Stock index futures can also be used as a tool to hedge the risk of stock portfolio, that is, hedging can transfer the price wind and hedgers to speculators. This is an economic function of the futures market. Hedging is J futures to fix the value of investors' stock portfolio: if the stock price in the portfolio changes with the price, the loss of one investor can be hedged with the profit of another investor. If the profits j are not equal, this kind of hedging is called complete hedging. In the stock index futures market, complete hedging brings risk-free returns. In fact, hedging is not that simple; To get a complete hedge, hold a stock group! The reporting rate must be completely equal to the yield of stock index futures contracts. Therefore, the effectiveness of hedging is determined by the following factors: (1) The relationship between the fluctuation of the declared interest rate of the investment portfolio and the direction of the return rate of the stock market futures contract refers to the risk coefficient (β) of the portfolio; (2) The difference between the commodity price and the futures price is called the basis point. During hedging, the basis point may be large or small. If the basis point changes (which is very common), there can be no complete hedging. The greater the change in the basis point, the smaller the chance of complete hedging. At present, there are no futures contracts for stock accumulation, and the only market that provides designated stock index futures at present. The behavior of investors will affect the success rate of hedging. Whether the stock portfolio price in hand follows the change of the gap between the index and the basis point will be beneficial to the success rate of hedging. There are basically two kinds of hedging transactions: selling hedging and buying hedging. Selling hedging is used to protect the future decline of stock portfolio price. Under this kind of hedging, the hedger can fix the future cash price by selling the futures contract, and transfer the price risk from the holder of the stock portfolio to the buyer of the futures contract: one of the situations of selling hedging is that investors expect the stock market to fall, but ignore their own stocks; They can short stock index futures to make up for the loss of holding stocks: buy hedges to protect the future price changes of stock portfolios. Under this kind of hedging, the hedger buys futures contracts, for example, the fund manager predicts that the market will rise, so he wants to buy stocks; But if the funds used to buy stocks can't be put in place immediately, he can buy futures indexes, and when the funds are enough, he will sell futures to buy stocks, and the futures income will offset the cost of buying stocks at high prices.