Company Seeks to Replicate Successful Approach with Traders and Trading Community Among Listings Community and Corporate America

CHICAGO – September 16, 2004 – Well-known for cutting edge advertising that quickly helped build the Archipelago brand and drive its success among the equity trading community, The Archipelago Exchangesm (ArcaEx),* the nation's first totally open, all-electronic stock exchange, today announced the launch of its first-ever advertising campaign targeted to Corporate America.

ArcaEx's the ‘Numbers This Big Are Hard To Ignore' campaign focuses on generating initial awareness of the company among corporate issuers interested in both primary and dual listings. The campaign features both print and television executions. The television advertisements themselves focus on situations where individuals are involved in innocent, everyday activities from feeding birds in the park to a chess match, yet are soon overcome by a magnitude of interest from other parties that are drawn to the activity. The tagline identifies ArcaEx as the world's largest fully-electronic stock exchange. Specifically ‘Numbers This Big Are Hard to Ignore' refers both to the drawn masses that assemble in the commercials and more literally to the trade volume and dollar amounts that change hands on the Archipelago Exchange every day. One execution notes the exchange's average daily volume of 575 million shares traded, while another places a $14 billion number on U.S equities traded daily.

The advertisements first ran today in the Wall Street Journal's special section on the Ryder Cup and continue through mid November including as many as 15 Ryder cup spots between NBC and USA networks this weekend. Other print media include the New York Times, San Jose Mercury News, American Banker, The Deal, IR Magazine and others. Other broadcast media will include ESPN, CNN, FOX and CNBC. Many of the media placements represent first-time placements for Archipelago – in line with the company's focus on targeting a new corporate audience.

“In 1997 we were a relatively unknown entity within the trading community – today unaided awareness of Archipelago within this group is on par with the NYSE,” commented Margaret Nagle, Marketing Director of Archipelago. “With traders we initially focused on awareness building and years later on differentiation. We intend to attack the corporate marketplace in the same way.”

Nagle continued, “These efforts are focused on making CEOs, CFOs, investor relations officers and key outside influencers to the listings process aware of ArcaEx. We hope they will be interested in probing further about the listing services ArcaEx provides.”

Jerry Putnam, CEO of Archipelago commented, “We worked hard to get to a point where we could offer issuers the market structure, tools and services that make us a viable entrant in this arena.” Putnam added, “As one of the dominant companies in the equities trading business we frequently trade more Yahoo, eBay, Dell and other securities than does the marketplace they call home. This extra volume per se offers listed companies unparalleled insights into their stock trading – insights we believe CEOs, CFOs, IR directors and others will find of great value. We think we can offer a unique value proposition to new issuers and potential dual listings.”

The advertising campaign marks ArcaEx's most public efforts to date to raise awareness of its listing services. In the last 18 months the exchange has put in place a corporate client group which includes some former members of the NYSE and Nasdaq listings effort. This group's focus is in on attracting issuers to ArcaEx and providing information tools of interest to issuers.

Fallon Minneapolis created the advertisements.

About the Archipelago Exchange

Archipelago Holdings, Inc. (PCX: AX) owns and operates the Archipelago Exchange (ArcaEx). ArcaEx is the first totally open all-electronic stock market in the United States. Through its alliance with the Pacific Exchange, Inc., Archipelago operates ArcaEx as the exclusive equities trading facility of PCX Equities, Inc. Through ArcaEx, Archipelago customers can trade over 8,000 equity securities, including securities listed on the New York Stock Exchange®, Nasdaq®, American Stock Exchange® and Pacific Exchange®. ArcaEx is regulated by the Pacific Exchange. The Archipelago ECN, a precursor to ArcaEx, was one of the four original ECNs, formed in December 1996 with Townsend Analytics.

Certain statements in this press release may contain forward- looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements are based on the company's current expectations and involve risks and uncertainties that could cause the company's actual results to differ materially from those set forth in the statements. There can be no assurance that such expectations will prove to be correct. Factors that could cause the company's results to differ materially from current expectations include: general economic and business conditions, industry trends, competitive conditions, regulatory developments and the additional factors and risks contained in the Company's Prospectus and other documents filed with the Securities and Exchange Commission, which are available on the company's website

Contact:
Nevin Reilly
Sloane & Company
212-446-1893

* ArcaEx is regulated by the PCX, a registered exchange. While ArcaEx provides listing services, all listings are on the PCX.