Shanghai and Shenzhen 300 futures refer to the stock index futures to be launched by CICC. However, it is still in the simulation stage and has not been officially listed. If you want to do stock index futures, you'd better open an account in a futures company, and the cost will be cheaper, because stock index futures are a variety of futures, not stocks. It will be very helpful for you to know more about the trading rules of futures before doing futures. If necessary, we can exchange views with each other.