CBOE Announces Purchase Of CBOE Membership Owned By Former Vice Chairman Edward Tilly

The Chicago Board Options Exchange announced its purchase today of the CBOE membership owned by former Vice Chairman Edward Tilly for a price of $1,360,000.00. This price equaled the previous last sale, on August 4, 2006. This price fell between the next highest bid and next lowest offer that had been submitted immediately before this sale.

CBOE's Board approved the Exchange's purchase of this membership in connection with Edward Tilly's assuming the position of CBOE's Executive Vice Chairman. (The Exchange's rules restrict an officer, other than the member Vice Chairman, from being a member or affiliated with a member). The Exchange purchased Mr. Tilly's membership in light of the possibility that Mr. Tilly, as a former Vice Chairman, may have had access to information that would not have been known to another purchaser.

The Exchange will hold the membership in treasury until it makes a determination regarding the most appropriate use of the membership, which may include its use in connection with an alternative management pension plan investment vehicle. At this time, the Exchange does not have any plans to purchase additional memberships.

CBOE, the world's largest options marketplace and the creator of listed options, is regulated by the Securities and Exchange Commission (SEC). For additional information about the CBOE and its products, visit the CBOE website at: http://www.cboe.com/