to lose your shirt
carsten: i feel so sorry for luke smith and his family.
tiffany: he's your classmate, right? did somebody die?
carsten: no. his father invested almost all his money in a financial scheme that was supposed to make him a lot of money without any risk.
tiffany: i've heard about schemes like that. they're all swindles. so what happened?
carsten: he lost his shirt. he didn't make a cent out of it and lost all the money he put in.