On September 13th, the SEC granted immediate effectiveness to the Chicago Board Options Exchange's proposal amending CBOE Rule 6.53C, which governs the operation of the Exchange's electronic complex order book ("COB") system. The proposed rule change would provide the Exchange with additional flexibility to determine the applicable matching algorithm for option classes in which COB is activated. Comments should be submitted on or before October 8, 2010. SEC Release No. 34-62897.