September 15, 2008: Lehman Brothers went bankrupt after the Federal Reserve declined to guarantee its loans, causing the Dow Jones to drop 504 points, its worst decline in seven years. The same day, Bank of America purchased Merrill Lynch.
In 2008, the DJIA loses more than 500 points on September 15 amid fears of bank failures, resulting in a permanent prohibition of naked short selling and a three-week temporary ban on all short-selling of financial stocks; in spite of this, record volatility continues for the next two months, culminating at 5+1⁄2-year market lows.