Liar's Poker is a non-fiction, semi-autobiographical book by Michael Lewis describing the author's experiences as a bond salesman on Wall Street during the late 1980s. First published in 1989, it is considered one of the books that defined Wall Street during the 1980s, along with Bryan Burrough and John Helyar's Barbarians at the Gate: The Fall of RJR Nabisco, and the fictional The Bonfire of the Vanities by Tom Wolfe. The book captures an important period in the history of Wall Street. Two important figures in that history feature prominently in the text, the head of Salomon Brothers' mortgage department Lewis Ranieri and the firm's CEO John Gutfreund.

Liar's poker is an American bar game that combines statistical reasoning with bluffing, and is played with the eight digits of the serial numbers on a U.S. dollar bill. The numbers are usually ranked with a zero counting as a ten, and a 1 being highest as "ace". Normally the game is played with a stack of random bills obtained from the cash register. The objective is to guess how often particular digits appear across all bills held by players, with guesses increasing in value or quantity until a player challenges the most recent guess.