Straight flush does not belong to any securities company, but is developed by an independent straight flush company which specializes in researching and developing stock software. I am using this software now, and I think it is very easy to use. Of course, as long as you open a stock account and the Flush supports the entrusted trading system of the brokerage firm where you open the account, you can use your stock account to make firm trading on the software of the Flush. Of course, at present, the software of official website Straight Flush supports the firm trading of most domestic brokers.
I hope my answer can help you. I hope it can be adopted. Thank you.