ISE Reports Monthly Volume for March 2007.

Record Monthly and Quarterly Average Daily Volume of 2.8 Million Contracts

NEW YORK -- The International Securities Exchange (NYSE:ISE) today reported that average daily trading volume for equity and index options contracts for March 2007 increased 32.4% to a record 2.8 million contracts as compared to 2.1 million contracts during the same period in 2006. Total equity and index options volume for the month increased 26.7% to 62.3 million contracts from 49.2 million contracts in the same year-ago period.

On a year-to-date basis, average daily trading volume of equity and index options increased 16.3% 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 March 2007 increased 14.5% to 169.2 million contracts from 147.8 million contracts in the same period last year.

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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 March would increase to 30.8% from 30.2%, an increase of 0.6 market share points.

On a year-to-date basis, our market share would increase to 31.5% from 30.2%, an increase of 1.3 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 March.

* On March 5, 2007, ISE and TSX Group announced the creation of DEX[TM], a new Canadian derivatives exchange. DEX, which is scheduled to begin operations in March 2009, will be owned 52% by TSX Group and 48% by ISE and will list and trade options, futures and options on futures on a range of Canadian securities.

* On March 9, 2007, ISE traded its 2 billionth options contract. This trade, which was in the Nasdaq-100(R) Trust Shares (QQQQ), took place between Penson Financial Services, Inc. and Ronin Capital, LLC.

* On March 27, 2007, ISE announced a partnership with Optionetics, Inc., a recognized leader in options education, in a joint effort to educate retail investors about ISE FX Options[TM]. Optionetics will incorporate information and trading strategies for ISE FX Options into its two-day seminar series Trading the Foreign Exchange Markets, which are executed by its affiliate FX Trading Education Corp. (FXTE).

* On March 28, 2007, ISE announced that Timber Hill LLC, the market making subsidiary of Interactive Brokers, will serve as the Primary Market Maker (PMM[R]) for the first four currency pairs of ISE FX Options that will be listed on the Exchange. Additionally, Citigroup Derivatives Markets Inc., Lehman Brothers Inc., and Optiver US, LLC will act as Competitive Market Makers (CMMs[R]) in a variety of the products. Trading will initially take place in the following four currency pairs: USD/EUR (Symbol: EUI), USD/GBP (Symbol: BPX), USD/JPY (Symbol: YUK), and USD/CAD (Symbol: CDD).

* ISE traded more volume than any other options exchange in 899 of 1,721 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] are slated to launch in 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 December 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.