Lehman Brothers' September 2008 bankruptcy became the largest in U.S. history at that time.
Lehman Brothers filed for Chapter 11 bankruptcy protection on September 15, 2008, reporting more than $600 billion in debt. The firm had built substantial exposure to mortgage-related assets and was unable to secure a buyer or government-backed rescue. Its failure intensified the global financial crisis and caused severe stress in credit markets.
The bankruptcy followed the collapse of Bear Stearns in March 2008, but the two events were different. JPMorgan Chase acquired Bear Stearns with government support, whereas Lehman entered bankruptcy. Merrill Lynch was acquired by Bank of America in the same September weekend.
Lehman's failure did not alone create the entire crisis. It was one of several linked events involving housing losses, leveraged financial institutions, short-term funding, and declining confidence. The U.S. government later supported the insurer AIG and created the Troubled Asset Relief Program.