Many people have no idea about the commission fee. Here is a brief introduction. For example, if the principal is 2000u, and the order is 20 times, the order is 40,000u. Buy 20u, sell 20u, a total of 40u. If there are 3 orders a day, the daily commission is 120u. The annual commission is 43,800u, which is only 2000u principal, and it is only opened 20 times. If you open 40 times each time, the commission will double, and it will be 87,600u a year. So you must open the commission refund. How much you can get back is free. After opening, if you return 20, as long as you keep the principal, you can return 8760u in commission. If you earn 2000, then 2000+8760 equals 10760. If you accidentally blow up your account, the commission refund will still bring you a certain amount of principal.