How come he lost everything one day? Do most of the gamblers lose money in such way?
When it comes to playing, there are times that you will win, but we all know that after all those winning, you will suddenly lose because luck is not on your side everytime.
What you are saying is that called" Beginners Luck" in which most newbies has given opportunities and experience the winnings but just after that the Losses starts and they will become addicted to chase those wins from the past.
In this case, your friend might have face his losing streak and tried to take his losses back, unfortunately, your friend wasn't able to do that and end up losing all his money.
He is not chasing losses because he wins more than what he has as capital what happens here is that OP's Friend becomes Greed to chase for more wins and not leaning back about the losing he got.