Forced liquidation: refers to the trading behavior that one party uses the advantage of capital or warehouse receipt to guide the market to move unilaterally, resulting in the other party's continuous losses, and finally has to cut its position. Generally divided into two forms: forced empty warehouse and forced empty warehouse. Forced liquidation is a kind of market manipulation, mainly by manipulating the spot market and futures market to force opponents to submit, so as to achieve the purpose of profiteering.

Open position: refers to the risk that the customer's equity in the customer's account is negative, that is, the customer not only loses all the margin in the account before opening the position, but also owes money to the futures company.