The Securities and Exchange Commission approved new exchange rules that implement uniform standards for breaking trades that are deemed to be “clearly erroneous.” Clearly erroneous execution rules had varied from exchange to exchange and in many cases were based on the subjective judgment of exchange officials. The exchanges, led by NYSE Arca, worked together with SEC staff to develop a set of more objective “model” rules. Such rules were recently adopted, with immediate effectiveness, by BATS Exchange, the Chicago Board Options Exchange, Chicago Stock Exchange, International Securities Exchange, NASDAQ Stock Market, the NASDAQ OMX BX, National Stock Exchange, New York Stock Exchange, NYSE Amex, and NYSE Arca.

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