Shorting a lot of people don't understand and it's hard to explain. Even if there is no rice, you sell rice and you sell it for 2 yuan. Fortunately, someone wants to buy it, and then you go somewhere else 1 yuan to buy rice, and finally give it to that person. This is very short. Simply put, as long as you firmly believe that the price will fall, even if you don't have the goods, you can short them and buy them back at a low price, thus making a profit. That's what we do in the futures market. The same is true of the foreign exchange market. So can future stock index futures. But now stocks can't be substantially short, so many people sell stocks and say they are short.