Backhand is to flatten the original position of the customer at the current price, and immediately reopen the position for the customer at the current price system. For example, the customer has already held 1 hand rebar, and the thread price has dropped to 3900. The customer thinks it will not go up, but it will go down. He wants to close the position and open an empty order as soon as possible, so he can choose backhand to close the original multiple orders at the price of 3900, and then the system will help the customer re-open the empty order at the price of 3900. Because the futures market price changes quickly, it may be a few points before closing the position and reopening the position in the opposite direction. So the function of backhand is also very important.