This might be the generic answer, but it depends on the player andbthevkevek of involvement they have in the game.

Any activity that requires staking money for possible return is enough to cause some level of thrill for the player cause they have something at stake and potentially have some amount to win. When you narrow that down into a game of few hours or even minutes the thrill rises automatically.

Gambling and trading both have their appeal and judging by the fact that both can get addictive, it is associated with a release of dopamine due to the thrill it causes.

If I'm to add something to your question, gambling is also a strategic challenge just as trading is and it requires a lot of critical thinks and consideration of past events.