The Big Short tells the story of the 2007 housing market crash and how a few key characters, who are based on real-life people, significantly profited from the financial crisis. Michael Burry (Christian Bale) was at the center of it all since he was the one who predicted that the housing market would crash and used that information for his own benefit and to help out his investors. Burry founded the hedge fund Scion Capital, allowing others to profit off of the crisis that resulted in millions of lost jobs and homes.

https://screenrant.com/who-made-money-from-crash-the-big-short/