Lock-in refers to the futures investor opening a new position opposite to the current position and becoming a locked position. The popular saying is that an investor has made many orders before, but now he has made an empty order. Lock positions are divided into profit lock positions and loss lock positions. Profit lock refers to when investors have profited from previous positions, but feel that the current price may fall back and open new positions in the opposite direction; Loss locking refers to the loss of investors in the current position, but they can't see the development of the market outlook. First, they should reverse their position and wait and see. Generally speaking, it refers to an operation method in which futures traders open positions in the same amount but in the opposite direction, so that no matter where the futures price changes (rises or falls), the position profit and loss will not increase or decrease.