Short selling is simply: if there is no goods, sell them first and then buy them. For example, if you see A shares 10 yuan, it will fall to 8 yuan within a certain period of time, but you don't own A shares. At this time, you can borrow some A shares from A-share holders and sign an agreement to return these borrowed shares to the original holders within a certain period of time. Suppose you borrow 100 A shares at the price of10 yuan. Get 1000 yuan in cash. If the stock really falls to 8 yuan within the specified time, you use 8 yuan to buy 100 A shares, spend money to buy 800 yuan, and return 100 shares to the original holder. The number of shares of the original holder remains unchanged, and you earn 200 yuan cash. At present, there is no short-selling mechanism in China, but the upcoming stock index futures are also short-selling mechanisms. The short-selling mechanism not only refers to the short-selling of stocks, but also includes the short-selling of indexes.

Gold futures and gold T+D use margin trading and introduce short-selling mechanism, so suppose that the current gold price is 250 yuan/gram, and you are short, that is, you buy down. When gold really falls to 200 yuan/gram, you earn 50 yuan/gram.

As for the specific trading of futures, interested friends may wish to communicate more.