Investing is about managing risk before chasing returns.
Diversification is key, but it requires covering all data points. But, human can't cover all data points. Human can't manage risk in real-time, 24/7.
Fund managers talk about returns.
But what you get is a roller coaster ride.
Your fund manager is in the front seat and does not know when the next drop is.
You pay high fees for their fun.
That is what investing should be, not "speculating" or "gambling"!