ISE Reports Monthly Volume for April 2007.

Average Daily Volume of 2.7 Million Contracts

NEW YORK -- The International Securities Exchange (NYSE:ISE) today reported that average daily trading volume for equity and index options contracts for April 2007 increased 14.7% to 2.7 million contracts as compared to 2.4 million contracts during the same period in 2006. Total equity and index options volume for the month increased 20.8% to 54.6 million contracts from 45.2 million contracts in the same year-ago period.

On a year-to-date basis, average daily trading volume of equity and index options increased 15.9% to 2.8 million contracts traded as compared to 2.4 million contracts traded in the prior year. Total year-to-date equity and index volume through April 2007 increased 15.9% to 223.8 million contracts from 193.0 million contracts in the same period last year.

Equity and Index Options Volume Statistics

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Equity Options Volume Statistics

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Index Options Volume Statistics

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Dividend Trade Activity

Our market share statistics continue to be negatively impacted by trading activity related to dividend trades among certain options market makers. These trades temporarily inflate and distort trading volume and market share when transacted. If the volume from the largest dividend trades were excluded from the data, our market share of equity options for the month of April would increase to 30.7% from 30.2%, an increase of 0.5 market share points.

On a year-to-date basis, our market share would increase to 31.3% from 30.2%, an increase of 1.1 market share points, if the volume from the largest dividend trades were excluded. The exclusion of dividend trades from total industry volume data presents a more relevant measure of the relative trends in our business.

Monthly Highlights

* ISE was the largest U.S. equity options exchange in April.

* On April 2, 2007, ISE announced that David Krell, its President and Chief Executive Officer, will retire on January 1, 2008. Upon his retirement, Mr. Krell will remain on ISE's Board of Directors, pending required approvals. Gary Katz, ISE's Chief Operating Officer, will succeed Mr. Krell as President and Chief Executive Officer.

* On April 17, 2007, ISE successfully launched trading in ISE FX Options[TM] in four currency pairs: U.S. Dollar/Euro (Symbol: EUI), U.S. Dollar/British Pound (Symbol: BPX), U.S. Dollar/Japanese Yen (Symbol: YUK), and U.S. Dollar/Canadian Dollar (Symbol: CDD).

* On April 30, 2007, Eurex and ISE announced that they have signed a definitive agreement under which Eurex will acquire ISE for approximately $2.8 billion in cash, or $67.50 per share. Pending receipt of regulatory approval by the U.S. Securities and Exchange Commission and other customary closing conditions, the transaction will create the largest transatlantic derivatives marketplace.

* ISE traded more volume than any other options exchange in 898 of 1,717 issues in its listings.

ISE Background

International Securities Exchange Holdings, Inc. (NYSE: ISE), through its subsidiaries, operates a family of innovative securities markets. ISE is founded on the principle that technology and competition create better, more efficient markets for investors and consists of an options exchange, a stock exchange and an alternative markets platform. ISE continually enhances its trading systems and develops new products to provide investors with the best marketplace and investment tools to trade smarter.

ISE developed a unique market structure for advanced screen-based trading systems and in May 2000 launched the first fully electronic US options exchange. Currently, ISE operates the largest U.S. equity options exchange and is among the leading options exchanges in the world. ISE offers index options, including a portfolio of proprietary index products, and enhanced market data products for sophisticated investors. ISE FX Options[TM] launched in the second quarter of 2007.

ISE Stock Exchange, launched in September 2006 with strategic partners, includes an innovative MidPoint Match[TM] platform which offers investors continuous price improvement. MidPoint Match was integrated with a fully displayed Best Bid Offer market in the fourth quarter of 2006.

ISE's alternative markets business currently consists of an events market trading platform known as Longitude. Longitude's patented and proprietary technology provides a unique parimutuel structure for derivatives auctions which results in greater trading and pricing flexibility for market participants.

For more information about ISE and its options exchange, visit www.iseoptions.com and for more information about ISE Stock Exchange, visit www.isestock.com. Additionally, to learn more about ISE alternative markets technology, visit www.longitude.com.

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.