Cutting positions is the behavior of stock brokers to trade their futures stocks with the stock futures market when the margin paid by customers is insufficient. In the stock futures trading market, short selling is generally carried out by paying margin. The deposit can be paid in cash or stock. When the stock price rises and falls, the margin falls below the minimum maintenance amount, that is, a margin reminder is sent to the customer, asking the customer to add the margin and close the position. When a customer borrows money from a securities company that pays a deposit to buy a certain stock futures, the customer cannot take away the purchased stock. Once the deposit paid by the customer is insufficient and there is no liquidity to make up the borrowed funds in time, there will be a situation of untimely liquidation. At this time, in order not to make their own interests suffer losses and take unnecessary risks, stock brokers will take the action of covering their futures stocks with the current market price to make up for their unpaid deposits. The Federal Reserve stipulates that the minimum maintenance amount of the deposit shall not be less than 50% of the market price of customers' short selling or short selling of stocks, and the minimum amount shall not be less than 2000 US dollars.