Option, also known as option, is a derivative financial instrument based on futures. The right to buy and sell in a certain period in the future means that the buyer has the right to buy and sell a certain number of specific subject matter to the seller at a predetermined price (referring to the performance price) in a certain period (referring to American options) or a certain date (referring to European options) in the future, but has no obligation to buy and sell.

The liquidation of the buyer refers to the liquidation of the option position, that is, the buyer exercises the right to buy the position (whether long or short) of a specific subject matter from the seller, so the liquidation is the position of a specific subject matter.