According to the price of existing orders in the exchange market, a certain number of orders are issued, and the orders hanging in the market are sold immediately. Pending orders, also known as single orders, refer to the process of filling in the name, quantity and price of assets to be bought or sold and submitting them to the trading system for trading. If there is no matching order in the market for the time being, then this order will always be hung on the opening of the exchange to provide quotations for the whole market.