One is pure speculation. The method mentioned by Brother f_bull upstairs is the most common method. For example, if you predict that the stock market will rise, you will make a buy order, and when the index really rises in the future, you will make a sell order, close your position and earn the difference between the two contract prices. Only predict the price drop, and do the opposite. The difficulty of this method lies in the need to accurately predict the market trend, and the risk is the greatest.
The second is to do it now. Simply put, it is to make money by using the abnormal price fluctuation between futures and spot. For example, the current Shanghai and Shenzhen 300 Index is 3,000 points, while the futures and contract trading prices in three months are 3,500 points. Then there was an abnormal price difference of 500 points between the two. Smart investors will seize this opportunity to sell a three-month futures contract at 3500 points in the futures market, and at the same time buy shares of the same value in the stock market according to the current quotation of 300 constituent stocks included in the Shanghai and Shenzhen 300 Index (etf index funds can also buy). In this way, after three months, no matter how the stock market fluctuates, this investor can guarantee a 500-point return. For example, three months later, the Shanghai and Shenzhen 300 rose to 4000 points, and the futures lost 500 points, but at the same time, they earned 1000 points in the stock market and made a net profit of 500 points. If the futures price is lower than the spot price, you can also buy futures and borrow shares from the stock exchange to sell them in the stock market (also known as securities lending) to earn the difference between the two.
The third is intertemporal arbitrage. This method mainly uses the abnormal fluctuation of contract prices in different delivery periods to make money. It is very similar to the principle of the previous set.
The fourth is cross-market arbitrage. This method mainly uses the abnormal fluctuation of the transaction price of the same contract in different futures markets to make money. For example, the transaction price of the same contract in the United States and Europe at the same time is sometimes different, and smart people can make money by using this difference. Of course, CICC is the only stock index futures exchange in China, so it is impossible to conduct cross-market transactions in China.
The latter three methods are called arbitrage trading. Arbitrage in foreign mature markets accounts for a large proportion, because this method has low risk and stable income, and institutions like these methods best.
Unable to expand due to text. If you are interested, you can consult relevant information, and the internet is also very rich and easy to understand. Good luck with your investment!