-you can't short sell
-the spreads are fukked because of their "zero fees"
-their market data and research resources are severely basic and lacking
-can't earn dividends
-they sell your activity to third party firms
Their gimmick is they are fast to sign up, streamlined app, and no deposit minimums. If you only have a rack to put up and just wanna sit on something like Tesla for awhile with limited knowledge, sure give it a go. But if you take it serious you will eventually get to a point where you want to deep dive more into companies, be more active day trading, and RH as a broker offers nothing worth using at that point.