Stock index futures contracts are continuous in the current month, continuous every other quarter, continuous in the next quarter and continuous in the next month. Are they four varieties divided by time? Stock index futures contracts are continuous in the current month, which is easy to understand. Delivery in the current month is also the main contract of the transaction. The number of people trading is relatively large, and the trading volume is also relatively large. Every other season's contract is continuous in the next quarter and in the next month. These are forward contracts, that is, they have a long term and can be held for a long time. It can only be studied as four variables, but if you do short-term, it is enough to look at the contract of the month and you can communicate more.