Which investment bank failed in September 2008, intensifying the global stock-market crash?

Lehman Brothers filed for bankruptcy on September 15, 2008, intensifying the global stock-market crash.

The firm was the fourth-largest investment bank in the United States and had accumulated major exposures to the mortgage and real-estate markets. As housing prices fell and mortgage-related securities lost value, confidence in Lehman’s balance sheet deteriorated. Negotiations for a rescue or sale failed, and the company filed the largest bankruptcy case in U.S. history at that time.

Lehman’s failure did not cause the entire financial crisis by itself, but it sharply increased fear about counterparty risk and the solvency of financial institutions. Merrill Lynch was acquired by Bank of America, while the U.S. government later provided assistance to AIG. The episode is often confused with Bear Stearns’ earlier collapse in March 2008; Bear Stearns was rescued through a JPMorgan Chase acquisition, whereas Lehman entered bankruptcy.