Lucas123 writes "The SEC and national securities exchanges announced a new rule that would help curb market volatility and help to prevent 'flash crashes' like the one that took place on May 6, when the Dow dropped almost 1,000 points in a half hour. That crash was blamed in part on automated trading systems, which process buy and sell orders in milliseconds. The new rule would pause trading on individual stocks that fluctuate up or down 10% in a five-minute period. 'I believe that circuit breakers for individual securities across the exchanges would help to limit significant volatility,' the SEC's chairman said. 'They would also increase market transparency, bolster investor protection, and bring uniformity to decisions regarding trading halts in individual securities.'"