Leverage mechanism and margin system are one of the most obvious differences between futures market and stock market. Generally speaking, the leverage mechanism is small and wide, which corresponds to the margin system in the futures trading system.

The margin system was determined by the Chicago Board of Trade when the standardized contract was launched in 1865, that is, the margin not exceeding 10% of the contract value was collected from both parties as performance guarantee.

Margin system is one of the bases to ensure market security. All buyers and sellers must be in deposits received to enter the futures market. Deposit is a performance bond, which proves the sincerity of the buyer or seller, helps to prevent breach of contract and ensure the integrity of the contract. The deposit can be cash, treasury bills allowed by the exchange, standard warehouse receipts, etc. Every customer has to pay a certain amount of trading margin to the futures brokerage company, and the brokerage company will deposit the customer margin into a special account to distinguish it from the company's own funds. Then, the brokerage company deposits the deposit in the exchange.

The margin required for buying and selling futures contracts varies, but it usually accounts for only a small proportion of the contract value, generally between 5%- 15% of the contract value. Generally speaking, the greater the price fluctuation of futures contracts, the more margin is needed. Traders do not need to pay the full contract value when trading, but only need to prepare the required margin to trade.