New SEC rules target ‘flash crash’

WASHINGTON – Federal regulators on Thursday put in place new rules aimed at preventing a repeat of last month’s harrowing “flash crash” in the stock market.

Members of the Securities and Exchange Commission approved the rules, which call for U.S. stock exchanges to briefly halt trading of some stocks that make big swings.

The major exchanges will start putting the trading breaks into effect as early as today, for six months. The New York Stock Exchange will begin today’s trading session with five stocks: EOG Resources Inc., Genuine Parts Co., Harley-Davidson Inc., Ryder System Inc. and Zimmer Holdings Inc. The exchange will gradually add other stocks early next week, expecting to reach by Wednesday the full number that will be covered.

The plan for the “circuit breakers” was worked out by the SEC and the major exchanges after the May 6 market plunge, which saw the Dow Jones industrials lose nearly 1,000 points in less than a half-hour.

Under the new rules, trading of any Standard & Poor’s 500 stock that rises or falls 10 percent or more in a five-minute period will be halted for five minutes. The “circuit breakers” would be applied if the price swing occurs between 9:45 a.m. and 3:35 p.m. Eastern time. That’s almost the entire trading day. But it leaves out the final 25 minutes before the close – a period that often sees raging price swings, especially in recent weeks as the kind of volatility that marked the 2008 financial crisis returned.

The idea is for the trading pause to draw attention to an affected stock, establish a reasonable market price and resume trading “in a fair and orderly fashion,” the SEC said.

On May 6, about 30 stocks listed in the S&P 500 index fell at least 10 percent within five minutes. The drop briefly wiped out $1trillion in market value as some stocks traded as low as a penny.

The disruption “illustrated a sudden, but temporary, breakdown in the market’s price-setting function when a number of stocks and (exchange-traded funds) were executed at clearly irrational prices,” SEC Chairman Mary Schapiro said in a statement. “By establishing a set of circuit breakers that uniformly pauses trading in a given security across all venues, these new rules will ensure that all markets pause simultaneously and provide time for buyers and sellers to trade at rational prices.”

Exchange-traded funds are increasingly popular investments that often track a market index such as the S&P 500 and can be traded throughout the day, unlike mutual funds. ETFs as a group were affected by the May 6 plunge more than any other category of securities.