The Dow Jones Industrial Average fell 998.5 points during the 2010 Flash Crash.
On May 6, 2010, the Dow dropped about 9% in a matter of minutes before recovering much of the loss. The episode affected U.S. equities, futures, options, and exchange-traded funds. Many securities briefly traded at extremely unusual prices, revealing weaknesses in market structure and liquidity.
A joint investigation by the U.S. Securities and Exchange Commission and the Commodity Futures Trading Commission concluded that a large sell order in E-mini S&P 500 futures interacted with high-frequency trading and automated systems. The precise pattern of events was complex, but the crash was not simply a normal response to a single news headline.
The Dow’s point loss is different from its percentage loss. Because the index was much higher in 2010 than in 1987, a smaller percentage move could produce a large number of points. Later rules added safeguards such as trading pauses and limits designed to reduce the chance of another sudden cascade.