What I am saying is that Ninja is a broker neutral front end trading system that can be used with many brokers' trading platform for ease of trading and some automation. You can have multiple accounts with multiple brokerages all in one platform. You chose which broker to direct your specific trade.
That being said, IB also has prime broker services where you can place trades with one broker and clear it thru IB, but that can getb a little expensive.
That being said, IB also has prime broker services where you can place trades with one broker and clear it thru IB, but that can getb a little expensive.