Futures main contract refers to the most active and easy contract in the market. Under normal circumstances, the contract with the largest position has the largest trading volume, and the position and trading volume are directly proportional to the variety activity. Investors are advised to choose varieties with high activity for trading.

A futures contract is an agreement in which the buyer agrees to receive assets at a specific price after a specified time, and the seller agrees to deliver assets at a specific price after a specified time. The price agreed by both parties to be used in futures trading is called futures price, the designated date on which both parties must conduct futures trading is called settlement date or delivery date, and the assets agreed to be exchanged by both parties are called "target".