Theoretical error. First of all, shorting the stock index is the performance of bearish stocks. If short-selling stock indexes are not allowed to hedge the loss of stocks, then there are only two ways to reduce the loss of stocks: crazy selling at low prices every day will lead to a crazy drop in stock prices and a run tide, then the stock market will plummet; Second, switch to other investment products to hedge stock losses, no matter which way is the same, money will not flow into the stock market to do more. For more discussion about stock index futures, please trust me privately.