Lehman Brothers’ collapse became a defining trigger of the global stock-market crash in 2008.
The U.S. investment bank filed for bankruptcy on 15 September 2008, making it the largest bankruptcy filing in U.S. history at that time. Lehman was heavily exposed to mortgage-related assets and was unable to secure a rescue or buyer acceptable to regulators and other parties.
Its failure intensified an already severe financial crisis. Credit markets froze, confidence deteriorated, and major stock indexes around the world fell sharply. Other institutions, including AIG, required emergency support, while governments introduced extraordinary lending, guarantees, and bank-rescue programs. Lehman’s bankruptcy is important, but it was not the sole cause of the crash: the crisis had built through the collapse of the U.S. housing bubble, excessive leverage, and losses linked to subprime mortgages. Bear Stearns had already failed earlier in 2008, while Merrill Lynch was acquired by Bank of America.