The trading volume of stock index futures is bilateral, and both trading volume and positions are calculated bilaterally. Bilateral means buying quantity plus selling quantity. Stock index futures refer to futures contracts with stock index as the subject matter, which is an investment to judge the rise and fall of stock index futures and obtain income.

The subject matter of stock index futures includes: Shanghai and Shenzhen 300 Index (the most important), Shanghai Stock Exchange 50 Index, China Stock Exchange 500 Index, China Stock Exchange 1000 Index, etc.