In the former, you expect you have some better than even odds of winning money -- otherwise you wouldn't be doing it. In the latter you clearly understand that the odds are against you. See how different those are?
We can argue about the ability to day-trade the cryptocurrency market, but it's hard to argue that the odds there are more clearly defined than in a casino. The reason there's a moving market is because we don't all agree on those odds.
Hold on a second. I never argued that the odds are more clearly defined. How in the world can you calculate political odds, legal odds, and other odds? Can you calculate odds on a commodities trade like oil? What happens if a war breaks out between Iran and Israel? If a new technology takes hold? All of these things are another way in which odds can't be calculated as cleanly as, say, a Blackjack hand.
That many in the HN crowd consistently compare stocks and now cryptocurrency to casinos, and pad their argumentation that casinos are the same or better with an underlayment of probability calculation -- that shows the inherent mathematical bias of folks in tech. For how can one ascribe odds to purely human factors? Here's a probability prediction: chances of this comment being voted down > 50%.