How do these guys have so much money.

I’ve gotten really into watching cash games at 1am on YouTube. The Venetian Poker cash games for example, are these guys playing with their own $100k? Even for someone successful in poker I’d imagine that’s still a very very big amount of money to risk on a poker game. I get it’s their job but they seem so comfortable losing sometimes… is there something I’m missing or are these guys literally risking their fortune every time they play a cash game?