In fact, in the spot market, there are only two orders. After buying, it is called selling more, and after selling, it is called empty. It is easy to understand how to do more. After buying something, wait until the price rises before selling it. What you buy is the price increase. It's a little hard to understand short selling. People will have doubts. How can they sell without anything in their hands? In fact, what is bought and sold in the spot market is a forward trading contract. It doesn't matter if you don't have the goods in hand. You can sell them first by paying a deposit. After the price falls, you can close the empty order by paying the bill, and the price you buy falls.