Stock Market Plunge, Stock Market Plunge Probe | featured news

A trading firm's use of a computer sell order triggered the May 6 market plunge, which sent the Dow Jones industrial average plunging nearly 1,000 points in less than a half-hour, federal regulators said Friday.

Futures trades by Waddell & Reed, a mutual fund based in Kansas, have been linked to the May 6 “flash crash” of the Dow.

The top securities regulator said no single event had been found to explain Thursday's mysterious market plunge, but the shocking drop was unacceptable and additional safeguards were coming.

As regulators sought to make sense of what was behind Thursday's wild gyrations in the stock market, some experts warned that Wall Street's effort to undo tainted trades could encourage the very behavior that led to the market plunge.