- All-Electronic Stock Exchange Enhances Market-Making for Electronic Trading;

New Capabilities to Benefit Market Makers, Corporate Issuers and Investors -

CHICAGO, April 26 /PRNewswire/ -- The Archipelago Exchange(SM) (ArcaEx(R)), the world's largest fully-electronic stock exchange today announced a new market making program that will encourage additional price improvement and supplemental liquidity for stocks traded on ArcaEx. The program is subject to approval by the Securities and Exchange Commission (SEC).

"We are redefining our existing market making capabilities to provide enhanced liquidity to the benefit of both corporate issuers and investors," said Mike Cormack, President of Archipelago. "Additionally, our market making functionality is linked to our electronic best execution model ensuring that better priced orders on the ArcaEx book or in the national market are not overlooked. Displayed limit orders will retain standing on a price and time priority basis."

By protecting best prices on all markets, ArcaEx's program will not only enable clients to achieve enhanced execution quality, but also ensure compliance with the trade-through protections approved by the SEC in Regulation National Market System (also known as Reg NMS) to be implemented in April 2006.

Proposed changes to existing market making capabilities include enhancements to ArcaEx's current Directed Order Process and the addition of a Lead Market Maker for stocks with a primary listing on the Pacific Exchange for trading on ArcaEx. Orders executed within the Directed Order Process are free of an ArcaEx charge for both the order sending firm and the Designated Market Makers. Market makers will have the ability to provide price improvement by using ArcaEx's existing order types and will receive automated protection of trade throughs against the ArcaEx displayed limit order book.

Additionally, on a monthly basis, ArcaEx will provide issuers and market makers with reporting tools to analyze the quality of markets and trading activity for each Designated Market Maker registered in its symbol (s).

About ArcaEx

Archipelago Holdings (PCX: AX) operates The Archipelago Exchange(SM) (ArcaEx(R)) the first totally open all-electronic stock exchange in the United States. ArcaEx trades all Nasdaq-listed equity securities and exchange listed equity securities, including those listed on the New York Stock Exchange(R), American Stock Exchange(R), and Pacific Exchange(R). In addition to offering core execution services, ArcaEx provides corporate clients with listing services and innovative data products. In 2004, Archipelago launched ArcaVision to provide corporate and trading clients with more transparent market data, analytical tools and access to market-wide and ArcaEx specific trading information. Archipelago Holdings completed its initial public offering in August 2004. For more information please visit http://www.arcaex.com.

Forward-Looking Statements

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 Archipelago's current expectations and involve risks and uncertainties that could cause Archipelago'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 Archipelago's results to differ materially from current expectations include: general economic and business conditions, industry trends, competitive conditions, regulatory developments as well as other risks or factors identified in the Company's filings with the Securities Exchange Commission, including its Report on Form 10-K for the fiscal year ending December 31, 2004 which is available on the Company's website at http://www.archipelago.com. You should not place undue reliance on forward- looking statements, which speak only as of the date of this press release. Except for any obligation to disclose material information under the Federal securities laws, Archipelago undertakes no obligation to release publicly any revisions to any forward-looking statements to reflect events or circumstances after the date of this press release.

Contact:
Archipelago
Margaret Nagle
312-442-7083
SOURCE The Archipelago Exchange
-0- 04/26/2005
/CONTACT: Margaret Nagle of Archipelago, +1-312-442-7083/
/Web site: http://www.archipelago.com /
(AX)