Lehman Brothers' September 2008 bankruptcy became a key trigger of the global financial crisis.
Lehman Brothers filed for Chapter 11 bankruptcy protection on September 15, 2008, after losses linked largely to mortgages and mortgage-backed securities undermined confidence in the firm. It was the largest bankruptcy filing in United States history at that time.
The failure intensified fear about counterparty risk and the health of banks worldwide. Credit markets seized up, stock markets fell sharply, and governments responded with emergency lending, guarantees, rescues, and stimulus measures.
Lehman was not the only failing institution. Bear Stearns had been rescued earlier in 2008, while American International Group received a government bailout shortly after Lehman's collapse. The bankruptcy became a symbol of the crisis, but the wider downturn reflected years of excessive leverage and housing-market imbalances.