ISE Announces Successful MidPoint Match(TM) Trading Simulation; Over 34 Million Shares Traded.

NEW YORK -- The International Securities Exchange (NYSE: ISE) today announced the successful results of its first MidPoint Match(TM) trading simulation. MidPoint Match is the introductory product of the ISE Stock Exchange LLC, slated for launch in September. Over 34 million shares changed hands during the one-hour session, which took place yesterday after the market's close and was open to all approved users of the ISE Stock Exchange.

Andrew Brenner, Head of ISE Stock Exchange, said "This successful event highlighted the interest from our members in MidPoint Match and underscored the system's readiness and our team's ability to support the stock exchange's imminent launch. We were pleased to offer this preview of MidPoint Match and welcomed the positive feedback received from participants."

MidPoint Match is an instantaneous, fully-automated and anonymous platform that executes equity orders at the midpoint price of the National Best Bid and Offer (NBBO) and delivers continuous price improvement to both the buyer and the seller. During yesterday's trading simulation, over 28,000 orders were entered in under one hour. All order types eligible to trade on the exchange were tested. The MidPoint Match platform functioned flawlessly and is fully prepared to launch pending SEC approval.

ISE Background

The International Securities Exchange (ISE) is an innovative securities market, founded on the principle that technology and competition create better, more efficient markets for investors. ISE is the largest equity options exchange and is among the leading options exchanges in the world. ISE developed a unique market structure for advanced screen-based trading systems and in May 2000 launched the first fully electronic US options exchange. The ISE Stock Exchange LLC will launch in the third quarter of 2006 with strategic partners, offering an innovative MidPoint Match(TM) platform, followed by a fully integrated displayed Best Bid Offer (BBO) market in the fourth quarter. ISE is also a majority owner of Longitude LLC, an innovative platform for events markets trading, and offers enhanced market data products for sophisticated investors.

ISE continually enhances its trading systems and develops new products, including index options and market data, to provide investors with the best marketplace and investment tools to trade smarter. For more information about ISE, its options products and its technology, visit www.iseoptions.com and for more information about the ISE Stock Exchange LLC, visit www.isestock.com.

Forward Looking Statements

Certain matters discussed in this press release are "forward looking statements" intended to qualify for the safe harbor from liability established by the Private Securities Litigation Reform Act of 1995. These statements relate to future events or our future financial performance, and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements, to be materially different from those contemplated by the forward looking statements. We undertake no ongoing obligation, other than that imposed by law, to update these statements. Factors that could affect our results, levels of activity, performance or achievements and cause them to materially differ from those contained in the forward looking statements can be found in our filings with the Securities and Exchange Commission, including our annual report on Form 10-K, current reports on Form 8-K and quarterly reports on Form 10-Q, as amended.