The Big Short is a 2015 American biographical crime comedy-drama film directed by Adam McKay and co-written by McKay and Charles Randolph. The film is based on the 2010 book The Big Short: Inside the Doomsday Machine by Michael Lewis, and shows how the 2007–2008 financial crisis was triggered by the United States housing bubble. The film stars Christian Bale, Steve Carell, Ryan Gosling, and Brad Pitt, with John Magaro, Finn Wittrock, Hamish Linklater, Rafe Spall, Jeremy Strong, and Marisa Tomei in supporting roles.

To explain financial instruments, the film features cameo appearances by actress Margot Robbie, chef Anthony Bourdain, singer-songwriter Selena Gomez, economist Richard Thaler, and others who break the fourth wall to explain concepts such as subprime mortgages and synthetic collateralized debt obligations. Several of the film's characters directly address the audience, most frequently Gosling, who serves as the narrator.

The Big Short began a limited release in the United States on December 11, 2015, followed by a wide release on December 23 by Paramount Pictures. A critical and commercial success, the film grossed $133 million on a $50 million budget and received acclaim for the performances of the cast (particularly that of Bale), McKay's direction, editing, and the screenplay. The film won the Academy Award for Best Adapted Screenplay in addition to nominations for Best Picture, Best Director, Best Supporting Actor (Bale), and Best Film Editing.