Trading is basically a gamble. Same thing as when you gamble for your favourite team, you gamble with your money directly with bitcoin. Instead of sportsbook, you are gambling in an exchange. Pretty much the same however you are more likely going to win in your "gamble" with trading instead of actual gambling
I think that when it comes to trading cryptocurrencies, and specially to daytrading, it is more accurate to compare it to the lottery. Betting on sport events is also associated with luck, but in this case you can also count on your own knowledge and experience.