I have often read on this website about separately managed accounts. What is the best business/legal structure for separately managed accounts?
Interactive brokers friends and family account will let you trade up to 15 accounts without you accepting money and having to register as ria.
Just because IB lets you do this, does not mean in your state you don't have to register as an RIA. You still must follow state securities laws if this is a securities business. If it's future's, you still have to follow NFA/CFTC rules.
Futures or Securities? Either way, I would set up an LLC as the Manager. Then you have to decide if you need to register.