In terms of the securities and futures system, China learns from the United States, and also operates separately, each doing its own thing. Maybe it belongs to the same boss, such as Shen Yin Universal Securities Company and Shenyin Universal Futures Company. But it cannot be said that futures companies can participate in securities trading, only indirectly.
What do you want? Do you want to open an account with an American futures company and then participate in securities trading in the American stock market? That won't do. Futures companies only have seats in the futures exchange.