It's just gambling. Might as well bet on coin tosses.
It's gambling if you have no idea, like the prof.
No one really has any idea, that's the thing lol. What makes people think they have an idea is that because it's generally on the up (for now), it is much easier to be lucky. Imagine being in a casino where all the games are rigged in your favour. Well, at least until they decide to rig them against you.
When it comes to trading and speculating, almost no one has any real idea what they are doing, apart from some very basic things that may save you from getting a really nasty pie in your face in the long term.
Like, gambling isn't without some slightly useful rules either. And there are some people who can effectively utilise these rules to some extent. But unless you are actually counting cards, which almost no one is doing (and the trading analogue to that is even harder), then you only have a vague inkling of an idea of what is going on and luck is the main factor. Just ask all the finance "experts" who lost everything after the stock market took a shit after the 2001 bubble!