RH pretends to be a "broker" and:
1. lets people trade "stocks" that aren't stocks the way people think they are. All (convenient) trades (for its HF clients) get internalized and never ever hit any lit market/exchange. The fact that this is possible is a general issue with the US stock market and lack of meaningful regulation and policing. This is not unique to RH: https://www.youtube.com/watch?v=wg8onYvJW3Q
2. its entire business model revolves around selling a "front running service" to RH's hedge fund clients, so they can front run RH's users/retailers (who are NOT clients) on every single trade. The front running service is called PFOF and is illegal in a lot of countries, but not in the US.
3. Literally turns off the buy button temporarily when it's convenient for its hedge fund clients to manipulate a stock price to go in their desired direction. This is so mind-blowing that I probably need to provide a source. Here it is one: https://www.investmentwatchblog.com/robinhood-president-sold...
too bad this is apparently not common knowledge. Let de down-voting by RHs few remaining social media managers begin.