Bank margin account, also known as overdraft account; Credit account. An account opened by an investor in a securities company. Through this account, investors can use stocks as collateral, borrow funds from securities companies and invest according to a certain proportion of the total market value of the assets in the account.

In stock index futures trading, in order to ensure the performance and safeguard the legitimate rights and interests of both parties, the margin trading system is implemented. Anyone who participates in stock index futures trading, whether the buyer or the seller, must pay the deposit according to the regulations of the exchange where he is located. Margin is the financial guarantee for the trader to perform the contract.