Trading advisory - Regulatory system

Hello guys!
I have a question relating to cryptos speculation and regulatory system. Let me explain.

If I want to create a society which has the scope to take money (fiat) from people and invest it in ETF, Stocks, Forex etc, I need to be a broker (intended as a qualified person recognized by the law and allowed to do that). If I am NOT a broker, I am breaking the law. Correct?

What if I do the same with cryptos? I mean: people send me bitcoin or whatever to be invested because they trust that I can make their money grows. Am I allowed to do that although I am not a broker? How is the system regulated?

Please, it is not related to trust, risk, volatility of cryptos, impossible-to-do-that-because-nobody-knows-how-the-market-will-behave. It is just a doubt I have in terms of regulations. Can you help me to understand, please??

Thanks a lot