The futures lock-in function only exists in investments that can be traded in two directions. Usually used to hedge open positions. If you don't click Lock Hedge, you can directly place a reverse order in the same currency group on the opened position, which will result in a relative write-off with the original position. 1. Strictly speaking, a lock list refers to warehouse receipts with the same price and the same number of lots in different directions, but in practice, few people do this unless a novice places a wrong order. 2. In order to prevent the huge fluctuation of the opening of the next day, the general lock list finds a reasonable price locking risk before the closing of the first day and unlocks it according to the opening situation of the next day. This method is generally a large capital operation. Example: February 1, the market was bullish, and the price rose to 2550 before the afternoon closing. It is expected that the price will rise again the next day, so I decided to hold a position overnight, but I was worried that the CBOT market would plummet at night, which would affect the trend of the next day, so I made a selling position at 2550 and locked in a profit of 50 points. If CBOT rises at night and opens the next day, I will close my position and sell it. 3. Arbitrage also uses the method of locking orders; For example, cross-month arbitrage and cross-species arbitrage, here I will only say one as an example. When the price of a variety deviates from the price in recent months, it will be much larger or smaller than usual. For example, there is a difference of 700 between soybean 805 and soybean 809 due to fundamental factors. At this time, we analyzed that the price difference is very unreasonable, and the price difference must return, with at least 300 points of profit. Then we sell at 2570 of soybean 805, buy at 2500 of soybean 809, and close the position when the spread returns to around 400. In a word, I think the real meaning of locking orders is to avoid big operational mistakes and get the greatest benefits.