U.S. Stock Exchanges Delay Expansion of Volatility Curbs Until Feb

(Bloomberg) — U.S. stock exchanges delayed the expansion of volatility curbs by two months, according to a notice fromNasdaqOMX Group Inc.

[See Also:Exchanges to Delay Limit Up/Limit Down Curbs From Trading Close

The marketwide system known as limit-up/limit-down, which is meant to prevent mistakes from prompting wide swings in stock prices, wont be expanded to cover the final 15 minutes of the trading session until Feb. 24, according toNasdaq. The extension had been planned for Dec. 8.

Regulators have been fine-tuning systems for curbing volatility since the flash crash of May 2010 briefly erased more than $800 billion in value from U.S. share prices. The limit- up/limit-down initiative replaces a system of share halts known as circuit breakers and has been phased-in since April.