Lehman Brothers was a major global investment bank that filed for bankruptcy in 2008. Lehman declared bankruptcy after massive losses from investments in housing assets, especially subprime and Alt-A mortgages. Lehman's high leverage ratio, a measure of assets to equity, increased from 24:1 in 2003 to 31:1 in 2007, leaving it vulnerable to even small declines in asset values. In the lead up to its bankruptcy, talks to sell Lehman to Barclays or Bank of America fell through, and with no buyer, Lehman filed for Chapter 11 bankruptcy protection on September 15, 2008, marking the largest bankruptcy in US history.