On which date did the 2008 financial crisis intensify after Lehman Brothers filed for bankruptcy?

The 2008 financial crisis intensified after Lehman Brothers filed for bankruptcy on September 15, 2008.

Lehman Brothers was the fourth-largest U.S. investment bank when it sought Chapter 11 bankruptcy protection. Its failure followed heavy losses connected to mortgage-related securities and the collapse of the U.S. housing market. The filing became the largest bankruptcy in U.S. history at that time.

Lehman’s collapse damaged confidence because financial institutions were deeply connected through loans and derivatives. Banks became more reluctant to lend to one another, and stock markets around the world fell sharply. The event is widely treated as a defining moment of the global financial crisis, although the crisis had already been developing for more than a year.

Lehman did not receive the same rescue as some other institutions. The U.S. government and Federal Reserve subsequently supported emergency measures for the financial system, including assistance for AIG and the Troubled Asset Relief Program.