1. There are two situations in which the exchange implements compulsory lightening: compulsory lightening in the case of continuous ups and downs and policy compulsory lightening. If the former is expressly stipulated in the trading rules of the exchange, it shall be implemented in accordance with the provisions; The latter is mostly due to the risk control measures taken by the competent authorities (CSRC) on the futures market, such as the plywood incident of Shanghai Commodity Exchange 1995, the red bean incident of Suzhou Exchange 1996 and the mung bean incident of Zhengzhou Exchange 1999.

2. According to the current trading rules of various exchanges, when there is a continuous price limit, the exchange will implement compulsory lightening measures. Specifically, after the end of the day's trading, the order quoted by the daily limit board (or the daily limit board) but failed to close the position was forced to close the position, and the opponent who closed the position was the profitable order holding the position on the contract (whether the customer holding the order is willing or not). The principle of closing positions is to start with the most profitable list until all pending orders (hanging at the stop-loss price) that have not been closed (before closing positions) are closed.

3. As can be seen from the above: a. The executor of compulsory lightening is the exchange; B. the price of lightening the position is the daily limit (or down limit); C. Are you willing to take the initiative to reduce your position (whether to declare)? As long as your position is profitable, it may be closed. The principle is "the more profitable, the more likely it is to be crushed".

4. For customers with two-way positions, if their net positions (long and short offset) are profitable, they may be leveled (partially or fully profitable net positions). However, two-way positions (that is, positions locked when empty orders are more or less) will not be forced to close positions, except for policy positions (for example, in the Suzhou Red Bean 1996 incident mentioned above, all positions locked by each customer were directly offset, and no handling fee was charged).

The net profit of each trader's position is easy to calculate, just like the customer's bill, there is basically no need for manual intervention when closing the position. The trading system of the exchange will automatically select the most profitable list (position profit and loss) and open pending orders.

The theoretical starting point of the exchange's forced liquidation is: for the orderly development of the industry, profitable customers give up a little interest, so that loss-making customers lose less, so that this market can run healthily and for a long time.