Something placed by a confident person

BET

Think of what you might put down when you're sure of an outcome, often involving money or stakes in a game. It starts with a wager.

A confident person might "place" a bet when they're sure of an outcome, like in gambling or a wager. The word "placed" hints at the action of putting down money or stakes, which is what you do with a bet. It’s a straightforward definition where the clue plays on the idea of confidence leading someone to risk something on a predicted result.