Exhibit 21

NYSE EURONEXT

SUBSIDIARIES AND AFFILIATES

Name	State/Jurisdiction of Incorporation
NYSE Group, Inc.1	Delaware
New York Stock Exchange LLC2	New York
NYSE Market, Inc.3	Delaware
NYSE Regulation, Inc.3	New York
Stock Clearing Corporation3	New York
Securities Industry Automation Corporation3	New York
NYSE TransactTools, Inc.4	New York
Archipelago Holdings, Inc.2	Delaware
Archipelago Trading Services, Inc.5	Florida
Archipelago Direct, L.L.C.5	Delaware
NYSE Liffe LLC6	Delaware
NYSE Liffe Holdings LLC1	Delaware
NYSE Arca, L.L.C.5	Delaware
Archipelago Market Data Services, L.L.C.5	Delaware
Archipelago Securities, L.L.C.5	Delaware
NYSE Arca Holdings, Inc.5	Delaware
NYSE Arca, Inc.7	Delaware
NYSE Arca Equities, Inc.8	Delaware
NYSE Technologies, Inc.2	Delaware
FINRA/NYSE Trade Reporting Facility LLC9	Delaware
Wombat Financial Software, Inc.10	Delaware
Harco Technology Ltd.11	England
Wombat Financial Software Europe Limited11	Northern Ireland
NYSE Alternext US LLC2	Delaware
Amex ETF Services LLC12	Delaware
American Stock Exchange Clearing LLC12	Delaware
PDR Services LLC12	Delaware
Amex Asset LLC12	Delaware
Amex Commodities LLC12	Delaware
Amex International LLC12	Delaware
American Stock Exchange Realty Associates LLC12	Delaware
Amex Realty Manager, Inc.13	Delaware
Amex Realty Borrower, LLC14	Delaware
NYSE Euronext (International) B.V.1	Netherlands
NYSE Euronext (Holding) N.V.15	Netherlands
Euronext N.V.16	Netherlands
Euronext Amsterdam N.V.17	Netherlands
Euronext France (Holding) S.A.S.17	France
Euronext Brussels S.A./N.V.18	Belgium
Euronext Lisbon—Sociedade Gestora de Mercados Regulamentados, S.A.17	Portugal
Euronext IFCS BVBA17	Belgium
Euronext Paris S.A.19	France
BlueNext S.A.20	France
Euronext Holdings U.K. Limited.17	United Kingdom
Euronext U.K. Limited.22	United Kingdom

Name	State/Jurisdiction of Incorporation
TransactTools Limited.22	United Kingdom
Archipelago Europe, Limited.22	United Kingdom
Euronext Indices B.V.23	Netherlands
Euronext Amsterdam International B.V.23	Netherlands
Euronext Amsterdam Clearing & Depository N.V.23	Netherlands
Euronext Amsterdam Intermediary B.V.24	Netherlands
Euronext Real Estate S.A./N.V.25	Belgium
Interbolsa—Sociedade Gestora de Sistemas de Liquidaçao e de Sistemas Centralizados de Valores Mobilarios, S.A.26	Portugal
S.E.P.B. S.A.19	France
La Financière Événement19	France
Euronext London Limited21	United Kingdom
LIFFE (Holdings) plc27	United Kingdom
The London Commodity Exchange (1986) Limited28	United Kingdom
Swapsconnect Limited28	United Kingdom
CScreen Ltd28	United Kingdom
LIFFE Ventures Inc.28	Delaware
LIFFE Ventures II Inc.28	Delaware
Secfinex Limited29	United Kingdom
NQLX LLC30	Delaware
LIFFE Futures plc28	United Kingdom
The London Futures and Options Exchange Limited28	United Kingdom
LIFFE (Nominees) Limited28	United Kingdom
LIFFE USA Limited28	United Kingdom
LIFFE Development Limited28	United Kingdom
LIFFE Services Limited28	United Kingdom
The Baltic Futures Exchange28	United Kingdom
B.F.E. Debenture Company No.1 Limited28	United Kingdom
LIFFE Options plc28	United Kingdom
LIFFE Limited28	United Kingdom
LIFFE Trustees Limited28	United Kingdom
London Traded Options Market Limited28	United Kingdom
LIFFE Administration & Management28	United Kingdom
Hugin Group B.V.19	Netherlands
Hugin SAS31	France
Hugin AS31	Norway
Hugin Norge AS32	Norway
Hugin Online A/S32	Denmark
Hugin ForetaksFakta AB32	Sweden
Hugin Investor Relations Services OY32	Finland
Hugin AG32	Switzerland
Hugin IR Services Deutschland GmbH32	Germany
Hugin (U.K.) Ltd.32	United Kingdom
Hugin IR Services B.V.32	Netherlands
Hugin Germany AG32	Germany
Imperium Centre Limited33	United Kingdom
Smartpool Holdings Limited34	United Kingdom
Smartpool Trading Limited35	United Kingdom
NYSE Euronext Technology Holding S.A.S.19	France
Atos Euronext Market Solutions Inc.36	New York
NYSE Technologies IPR Limited36	United Kingdom

Name	State/Jurisdiction of Incorporation
NYSE Technologies Limited36	United Kingdom
NYSE Euronext Technology S.A.S.36	France
NYSE Euronext Technology Connect B.V.36	Netherlands
NYSE Euronext Technology S.A./N.V.36	Belgium
Prime Source (NYSE Euronext) Limited28	United Kingdom
NYSE IP LLC	Delaware
Wall and Broad Insurance Company1	New York

¹ Wholly owned subsidiary of NYSE Euronext

² Wholly owned subsidiary of NYSE Group, Inc.

³ Wholly owned subsidiary of New York Stock Exchange LLC

⁴ Wholly owned subsidiary of Securities Industry Automation Corporation

⁵ Wholly owned subsidiary of Archipelago Holdings, Inc.

⁶ Wholly owned subsidiary of NYSE LIFFE Holdings LLC.

⁷ Wholly owned subsidiary of NYSE Arca Holdings, Inc.

⁸ Wholly owned subsidiary of NYSE Arca, Inc.

⁹ Wholly owned subsidiary of NYSE Market, Inc.

¹⁰ Wholly owned subsidiary of NYSE Technologies, Inc.

¹¹ Wholly owned subsidiary of Wombat Financial Software, Inc.

¹² Wholly owned subsidiary of NYSE Alternext US LLC

¹³ Wholly owned subsidiary of American Stock Exchange Realty Associates LLC

¹⁴ 99.99% owned by American Stock Exchange Realty Associates LLC and 0.01% owned by Amex Realty Manager, Inc.

¹⁵ Wholly owned subsidiary of NYSE Euronext (International) B.V.

¹⁶ 99.35% owned subsidiary of NYSE Euronext (Holding) N.V.; 0.62% owned by Euronext Paris S.A.; 0.03% owned by Euronext N.V.

¹⁷ Wholly owned subsidiary of Euronext N.V.

¹⁸ 80% owned subsidiary of Euronext N.V.; 19% owned subsidiary of Euronext Paris S.A.; 1% owned subsidiary of Euronext Lisbon—Sociedade Gestora de Mercados Regulamentados, S.A.

¹⁹ Wholly owned subsidiary of Euronext France S.A.S.

²⁰ 60% owned by Euronext Paris S.A.

²¹ Wholly owned subsidiary of Euronext Paris S.A.

²² Wholly owned subsidiary of Euronext Holdings U.K. Ltd.

²³ Wholly owned subsidiary of Euronext Amsterdam N.V.

²⁴ Wholly owned subsidiary of Euronext Amsterdam Clearing and Depository N.V.

²⁵ 99.84% owned subsidiary of Euronext Brussels S.A./N.V. and 0.16% are owned by Euronext Paris S.A.

²⁶ Wholly owned subsidiary of Euronext Lisbon—Sociedade Gestora de Mercados Regulamentados, S.A.

²⁷ Wholly owned subsidiary of Euronext U.K. Ltd.

²⁸ Wholly owned subsidiary of LIFFE (Holdings) plc

²⁹ 56.51% owned by LIFFE (Holdings) plc

³⁰ 98% owned subsidiary of LIFFE Ventures Inc.; 2% owned subsidiary of LIFFE Ventures II Inc.

³¹ Wholly owned subsidiary of Hugin Group B.V.

³² Wholly owned subsidiary of Hugin AS

³³ Wholly owned subsidiary of Euronext Holdings U.K. Ltd

³⁴ 72.83% owned by Euronext Holdings U.K. Ltd

³⁵ Wholly owned subsidiary of SmartPool Holding Limited

³⁶ Wholly owned subsidiary of NYSE Euronext Technology Holding S.A.S.