January 29, 2013 Immediately Effective C2 and CBOE Rule Changes New SRO rules and rule proposals have been announced by the SEC. Click on the links to view the SEC's notices of each rule change and proposal. C2: Effective Immediately - Rule Change Related to Pre-Opening Information CBOE: Effective Immediately - Rule Change Related to Pre-Opening Information Tags Regulated Entities Broker-Dealers Jurisdiction US - Federal