CHICAGO, Dec. 8 /PRNewswire-FirstCall/ -- Archipelago Holdings, Inc. (PCX: AX) today announced its November 2004 market transaction volume data for the Archipelago Exchange ("ArcaEx"). Specifically, in NYSE-listed equity securities, ArcaEx's total trading market share was up both year-over-year and sequentially, growing from 1.1% in November 2003 to 2.4% in November 2004 and from 2.3% in October 2004.

In AMEX-listed equity securities, ArcaEx's total trading market share grew from 13.0% in November 2003 to 25.9% in November 2004, and was down slightly from 27% in October 2004. ArcaEx's ETF total monthly share volume showed continued year-over-year growth with 1,557.8 (millions of shares) having traded in November 2004 compared to 555.7 (millions of shares) traded in November 2003.

    In Nasdaq-listed equity securities, ArcaEx's total trading market share

was down from 26.5% in November 2003 to 23.7% in November 2004 and from 25.1%

in October 2004.



                                   November       October        November

                                     2003          2004            2004



    Total monthly volume

     of Nasdaq-listed equity

     securities

     (millions of shares)          34,599.6       36,697.4       38,856.3

    ArcaEx monthly volume

     of Nasdaq-listed equity

     securities

    (millions of shares)(1)         9,165.0        9,198.3        9,203.0

    ArcaEx share of total

     monthly volume of

     Nasdaq-listed equity

     securities (%)(2)                 26.5%          25.1%          23.7%

    Total monthly volume

     of NYSE-listed equity

     securities

     (millions of shares)          31,097.3       40,286.5       39,634.4

    ArcaEx monthly volume

     of NYSE-listed equity

     securities

     (millions of shares)(1)          352.9          933.5          952.3

    ArcaEx share of total

     monthly volume of

     NYSE-listed  equity

     securities (%)(2)                  1.1%           2.3%           2.4%

    Total monthly volume

     of AMEX-listed equity

     securities

     (millions of shares)           5,366.1        6,629.2        6,654.7

    ArcaEx monthly volume

     of AMEX-listed equity

     securities

     (millions of shares)(1)          695.1        1,790.7        1,721.1

    ArcaEx share of total

     monthly volume of

     AMEX-listed equity

     securities (%)(2)                 13.0%          27.0%          25.9%

    ArcaEx ETF total monthly

     share volume

     (millions of shares)             555.7        1,659.0        1,557.8

    ArcaEx monthly customer

     order volume matched

     internally (%)(3)                 85.6%          87.0%          87.6%

    ArcaEx monthly customer

     order volume routed

     out  (%)(3)                       14.4%          13.0%          12.4%

    Number of trading days

     in period                           19             21             21





                       ArcaEx Most Active November 2004



                   Symbol                 Share Volume      Market Share

    Nasdaq-100 Index(R)       (QQQ)        661,359,507           33.4%

    Sirius Satellite Radio    (SIRI)       470,703,080           17.4%

    Microsoft(R)              (MSFT)       467,127,641           26.7%

    Intel (R)                 (INTC)       387,481,862           27.1%

    SPDR (R)                  (SPY)        292,842,690           30.4%

    Cisco Systems(R)          (CSCO)       270,864,353           23.3%

    Sun(R) Microsystems       (SUNW)       229,119,709           24.6%

    Semiconductor Holdrs(sm)  (SMH)        224,501,500           55.2%

    Applied Materials(R)      (AMAT)       207,704,977           25.5%

    Oracle(R)                 (ORCL)       163,350,952           24.2%

Additional information on ArcaEx daily, weekly and monthly trading transaction volumes is publicly available in real time through the ArcaVision website accessible via http://www.archipelago.com. Additional data and enhanced functionality can be obtained through a free subscription to ArcaVision. Investors and ArcaEx clients can subscribe to ArcaVision at http://www.arca-vision.com.

    (1)  For purposes of calculating monthly transaction volume on ArcaEx, we

      include all shares that are "handled" on ArcaEx for the month.  Handled

      shares include both shares that are bought and sold during the month

      within our internal liquidity pool and shares that are routed to

      external market centers for execution.



    (2)  ArcaEx monthly market share is calculated based on the number of

      shares handled on the ArcaEx system during the month as a percentage of

      total monthly volume. Total monthly volume is based on the number of

      shares of equity securities traded during the month on Nasdaq, AMEX or

      the NYSE, including if applicable exchange-traded funds, in each case as

      reported to the consolidated tape.  The "consolidated tape" is the

      system that continuously provides the last sale price and volume of

      securities transactions in listed securities to the public.



    (3)  In computing the percentage of monthly customer order volume matched

      internally and the monthly percentage of customer order volume routed

      out, we calculate the percentage based on the volume of individual

      customer orders, not the volume of matched trades (i.e., only counting

      one side of a matched transaction). For example, we calculate two

      customer orders matched internally on our system as two customer orders

      matched internally, and we include the volume of both the buy order and

      the sell order in computing our percentages of monthly customer order

      volume matched internally and routed out. We calculate one customer

      order routed to an external market center (which will be matched with an

      order at that other market center) as one outbound trade or one customer

      order. We calculate one customer order routed to us from an external

      market center and matched with an order on our system as one inbound

      trade or one customer order.



    About Archipelago Holdings

Archipelago Holdings (PCX: AX) operates The Archipelago Exchange(R) (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.archipelago.com.

ArcaEx's, past transaction performance is not necessarily indicative of its future results. Periodically, ArcaEX's transaction performance will experience fluctuations due to unforeseen factors effecting trading activity, including seasonality, general economic, political and market conditions, unforeseen market closures or other disruptions in trading. A description of the factors that may influence ArcaEx's volume of securities transactions are identified in Archipelago's Prospectus, dated August 12, 2004.

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 Archipelago's Prospectus, dated August 12, 2004, and form 10-Q dated November 9, 2004, each of which are filed with the Securities and Exchange Commission, and available on Archipelago's website: http://www.archipelago.com.

     Archipelago Contacts:

     Margaret Nagle - Press

     312-442-7083



     Patrick Murphy - Investor Relations

     312-442-7005

SOURCE  Archipelago Holdings, Inc.

    -0-                             12/08/2004

    /CONTACT:  Margaret Nagle, Press, +1-312-442-7083, or Patrick Murphy,

Investor Relations, +1-312-442-7005, both of Archipelago Holdings/

    /Web site:  http://www.archipelago.com

                http://www.arca-vision.com /

    (AX)



CO:  Archipelago Holdings

ST:  Illinois

IN:  FIN

SU:



WS

-- NYW127 --

6482 12/08/2004 12:31 EST http://www.prnewswire.com