Op is right, it all depends on the kind of gambler and how they handle excitement. Everyone with their different way of handling situation either sad mood or joyful mood, while some will say losing a bet can cause sleepless night I might consider winning a bet can as well cause such situation although I can’t relate but, I have seen people behave differently towards their win so not being able to sleep can be part of one. I’m curious if they stay awake all day watching their game or after playing the game what’s still the point staying awake, no doubt at that moment they think differently maybe after awhile they’ll realize is just a win.
It affects our sleep whenever we're winning and losing, so therefore that we shouldn't gamble so we can sleep. 
But it's true that it really depends on what kind of person we are. If we are so excited for every win that we make, that could also make ourselves and what are those? hormones, to be in a rush.
What makes us keep away from being asleep might be affected with how our emotions are mixing up.