Stock index futures are contracts designed according to the stock price index. Investors buy contracts when they look at multiple indexes, so if the index rises, it will be profitable, and if it falls, it will be a loss; Selling a contract when it is bearish, the profit and loss situation is the opposite of buying. At present, there are three kinds of stock index futures in China, with Shanghai and Shenzhen 300 Index, Shanghai 50 Index and China Securities 500 Index as the targets, which are introduced and managed by China Financial Futures Exchange.

Stock index futures implement margin system. Assuming that the margin ratio is 10%, it is enough to buy 1 stock index futures worth 900,000 yuan. If the stock price index rises by 10%, it means that it has earned 90,000 yuan and doubled its income. But if the index falls 10%, it will be all lost. In addition, stock index futures implement the T+0 system, which can be sold on the day of purchase, and the investment method is very flexible. After the end of each trading day, the futures company will settle the investor's account according to the settlement price of the day, and make up the deposit if the loss reaches a certain level.