CBOE Stock Exchange (CBSX) Volume Tops 3 Billion Shares Traded During 2008 - Growth In Volume, Listings And Participation - 2008 Highlights Include Lime Brokerage Investment, Functionality To Facilitate Automated Stock And Options Orders

The CBOE Stock Exchange (CBSX) announced today that more than three billion shares were traded at the Exchange during 2008, its first full year of trading.The Exchange, now 22 months old, had sustained growth in trading volume and the number of trades executed and continued to expand the number of market participants and products listed.

The CBSX multi-asset trading model was designed to increase the efficiency of trading combined stock and options orders, while reducing execution costs for market participants.CBSX enables options traders to either cross or interact with multiple equity traders at substantially increased speed, thereby reducing transaction costs and increasing performance and profitability.

David Harris, Chief Executive Officer of the CBOE Stock Exchange, said: "By any measure, 2008 was a successful year for CBSX.The increases across all performance gauges and market statistics indicate acceptance of our business model in a highly competitive environment for both order flow and technology offerings.The CBSX model is designed to execute equity hedging flow from the options community and to provide that community with reduced cost and latency in round trip trading.Equity traders also have the ability to access this 'untouched' options hedging flow.CBSX provides this capability using traditional and unique order types, delivered electronically over one platform."

"The launch of CBSX signaled our commitment to providing customers a choice in trading equities tied to options order flow," said William J. Brodsky, CBOE Chairman and CEO."The confidence that market participants have placed in CBSX in just two years of trading, underlines the value of the model.The Exchange's flexible systems will continue to make CBSX a unique trading venue."

Summary of Statistics:

Total and Average Daily Volume
The 3,604,649,431 shares traded during the twelve months of 2008 was an increase of 236 percent over the 1,072,401,400 shares traded during the Exchange's first ten months of operation in 2007.CBSX launched on March 5, 2007.Monthly trading volume in 2008 posted year-over-year gains versus each month of 2007.CBSX achieved record monthly volume of nearly 500 million shares in October 2008.

Average daily volume during 2008 was 14,426,626 shares per day, compared to the 4,272,516 shares per day in 2007.The 23.3 million shares traded per day in November 2008 currently stands as the highest monthly average daily volume on record at CBSX, while August 1, 2008 was the record volume for a single day with 50,205,700 shares traded.

Trades Executed at CBSX
During 2008, a total of 4,693,438 trades were executed at the all-electronic CBSX, up 183 percent and more than three million trades from 1,659,421 trades executed at CBSX during the previous year.In 2008, average trade size was 768 shares, a 19 percent increase from the 646 average trade size executed during 2007.

Product Lisitngs
At the end of 2008, CBSX listed a total of 6,288 securities -- both stocks and exchange traded funds (ETFs) -- for trading, up from the 4,000 securities at the end of 2007.When CBSX launched 22 months ago, 12 securities were listed on its first day of trading.Today, every single options contract available for trading at CBOE has a corresponding stock traded on CBSX.

Market Participants
Participation in CBSX's marketplace has grown steadily since going live.Presently, CBSX has 150 members -- market makers, firms that post liquidity, firms that send their equity hedging flow and firms that read and provide liquidity to the "Flash" -- trading on a daily basis on CBSX.

Highlights From 2008
In January, Lime Brokerage acquired a minority interest in the CBOE Stock Exchange.New York-based Lime Brokerage is a large liquidity provider catering to a diverse and sophisticated customer base including professional traders, hedge funds, asset managers and other broker-dealers.

In October, CBSX announced its buy-write program, which offers fully automated executions for combined stock and option trades through a single electronic platform.This new functionality enables the simultaneous execution of both the stock and option legs of any position trade in a one-to-one ratio -- all on the same electronic platform.This automated feature is especially advantageous for investors executing "buy-write" or "married put" hedging trades, but can be used for any trade that is combining different stock and option orders.Added benefits for traders include faster executions and the opportunity for price improvement.

CBOE Stock Exchange (CBSX) is a fully electronic, Regulation NMS compliant marketplace, offering strict price-time priority for all participants. CBSX offers trading in more than 6,300 of the most actively traded New York Stock Exchange, American Stock Exchange and NASDAQ Stock Market listed securities as well as Exchange Traded Funds (ETFs).CBSX is a subsidiary of the Chicago Board Options Exchange (CBOE).For more information about CBSX, including listings, access and fees, visit www.cbsx.com.