Gold t+d, an investment product, can be bought up or down, especially down. Many people don't understand why it can be bought. This is a trading rule, that is to say, gold is predicted to fall, bought and put down, and the result really falls. The more you fall, the more you earn. This is a popular saying. A more professional point is to sell a contract at a high price, such as 298, which is agreed to be sold to the other party at this price, but sometimes it is not implemented. Buy it when the price is lower, such as 288, and then fulfill the contract.