<PAGE>

                                                                     Exhibit 4.1

                                      ITG
                                  COMMON STOCK
                                 $.01 PAR VALUE

                            INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE

CUSIP 46145F 10 5
SEE REVERSE FOR CERTAIN DEFINITIONS

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                             THE FUTURE OF TRADING

                               [GRAPHIC OMITTED]

INVESTMENT TECHNOLOGY GROUP, INC.

                                               ---------------------------------
                                               INVESTMENT TECHNOLOGY GROUP, INC.
                                                           CORPORATE
                                                             SEAL
                                                             1983
                                                           DELAWARE
                                               ---------------------------------

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THIS CERTIFIES THAT






IS THE RECORD HOLDER OF

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FULLY PAID AND NON-ASSESSABLE SHARES OF THE COMMON STOCK OF INVESTMENT
TECHNOLOGY GROUP, INC. TRANSFERABLE ONLY ON THE BOOKS OF THE CORPORATION BY THE
HOLDER HEREOF IN PERSON OR BY ATTORNEY UPON SURRENDER OF THIS CERTIFICATE
PROPERLY ENDORSED. THIS CERTIFICATE IS NOT VALID UNTIL COUNTERSIGNED AND
REGISTERED BY THE TRANSFER AGENT AND REGISTRAR.

IN WITNESS WHEREOF THE CORPORATION HAS CAUSED THIS CERTIFICATE TO BE SIGNED BY
THE FACSIMILE SIGNATURES OF ITS DULY AUTHORIZED OFFICERS AND TO BE SEALED WITH
THE FACSIMILE SEAL OF THE CORPORATION.

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                                         FIRST CHICAGO TRUST COMPANY OF NEW YORK
                                                     (NEW YORK, NY)

/s/ Timothy H. Hosking   /s/ Raymond L. Killian, Jr.

                                         Transfer Agent and Registrar
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SECRETARY                PRESIDENT                     AUTHORIZED SIGNATURE
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         The following abbreviations, when used in the inscription on the face
of this certificate, shall be construed as though they were written out in full
according to applicable laws or regulations:

     TEN COM - as tenants in common
     TEN ENT - as tenants by the entireties
     JT TEN  - as joint tenants with right of
               survivorship and not as tenants
               in common

UNIF GIFT MIN ACT - __________________Custodian___________________
                          (Cust)                     (Minor)

                    under Uniform Gifts to Minors
                    Act__________________
                            (State)

    ADDITIONAL ABBREVIATIONS MAY ALSO BE USED THOUGH NOT IN THE ABOVE LIST.

For Value Received ____________ hereby sell, assign and transfer unto

PLEASE INSERT SOCIAL SECURITY OR OTHER
   IDENTIFYING NUMBER OF ASSIGNEE
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  (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE OF ASSIGNEE)


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------------------------------------------------------------------------- Shares
of the capital stock represented by the within Certificate, and do hereby
irrevocably constitute and appoint


----------------------------------------------------------------------- Attorney
to transfer the said stock on the books of the within named Corporation with
full power of substitution in the premises.

Dated_______________________


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                  NOTICE: THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH
                          THE NAME AS WRITTEN UPON THE FACE OF THE CERTIFICATE
                          IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT
                          OR ANY CHANGE WHATEVER.


  SIGNATURE(S) GUARANTEED:
                          ----------------------------------------------------
                          THE SIGNATURE(S) SHOULD BE GUARANTEED BY AN ELIGIBLE
                          GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS
                          AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH
                          MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE
                          MEDALLION PROGRAM), PURSUANT TO S.E.C RULE 17Ad-15.


  KEEP THIS CERTIFICATE IN A SAFE PLACE. IF IT IS LOST, STOLEN, MUTILATED OR
  DESTROYED, THE CORPORATION WILL REQUIRE A BOND OF INDEMNITY AS A CONDITION TO
  THE ISSUANCE OF A REPLACEMENT CERTIFICATE.