Lehman Brothers filed for bankruptcy on September 15, 2008, becoming a major trigger of the global financial crisis.
Lehman Brothers was a large American investment bank heavily exposed to mortgage-related assets. After the U.S. housing market deteriorated, the firm suffered major losses and struggled to raise enough capital or find a buyer. Its bankruptcy was the largest in U.S. history at the time.
The filing intensified fear across financial markets because institutions were unsure which counterparties were vulnerable. Credit markets froze, stock prices fell, and governments intervened to support banks and insurers. The failure is distinct from the earlier rescue of Bear Stearns and the government conservatorship of Fannie Mae and Freddie Mac.