I am currently using Interactive Brokers. My individual account grows to $500K size now. I am thinking that different brokers specialize in different account size. My question is that in what level, should I consider to switch to another broker that have better support for that account size? For example, go to TD Ameritrade? or some professional broker like Goldman Sachs? If you have experience and have the same though as me, please share with your thought. Thank you very much.