Lehman Brothers filed for bankruptcy on September 15, 2008, during the global financial crisis. The filing was the largest bankruptcy in U.S. history at that time, involving hundreds of billions of dollars in assets and intensifying panic in financial markets.
Lehman had built a major business in mortgage-related securities and was heavily exposed to the U.S. housing downturn. As house prices weakened and mortgage defaults increased, the value of those assets became increasingly uncertain. The firm struggled to raise capital or find a buyer acceptable to regulators and creditors.
Lehman’s collapse is often treated as a turning point in the crisis, but it was not the only failure. Bear Stearns had already been rescued in March 2008, while American International Group received emergency support soon after Lehman failed. The event also exposed how interconnected banks, insurers, funds, and global markets had become.