1, the number after the futures contract refers to the expiration month, for example, corn 1709 refers to the contract that expires in September of 20 17;

2. Futures trading should choose the main contract or the secondary main contract for trading. The method of judging the main contract is simple-the contract in the month with the largest position and turnover is the main contract, so that liquidity is guaranteed. If the positions and turnover in other months are low, it is easy to cause liquidity risk.

3. The main contract of futures contracts will change constantly, because as the contract approaches the expiration date, new main contracts will appear in the market, so investors also need to change the contract voluntarily.