What is the digital currency Contract? The principle of contract trading is the same as futures trading. Before any transaction, matters such as digital currency should be submitted and agreed by both parties, and then the transaction should be conducted at the agreed time. No matter when the trading time is up, whether digital currency has gone up or down, and whether the result is profit or loss, it must be traded according to the previous agreement. For example, BTC/USDT, if I am optimistic about BTC and think it is an upward trend in a short time, then I will buy more. I pay 20 USDT deposits to the platform, plus 5 times leverage, which is equivalent to buying BTC with 100 USD, and then selling it when it rises. At the same time, I will return the interest of the USDT principal I borrowed before to the platform, so that I can earn the difference of all BTCs I bought. Similarly, if I don't like BTC and think it is a downward trend for a period of time, then I will short it, and I will pay 0.2 BTC margin to the platform, with 5 times leverage. Then I will directly sell a total of 1 BTC for USDT, and then buy BTC and return it to the platform after the BTC falls, so that I can earn the difference of all the BTCs I bought. The above examples are all profitable. If you lose money, you will also lose all the price difference between BTC rise/fall. In addition, in order to understand the role of leverage, I used the Man Cang trade in the above example. In fact, in the actual contract trading process, it is not recommended to trade all positions.