Exhibit 3.3


                              AMENDED AND RESTATED

                                     BY-LAWS

                                       OF

                            MARKETAXESS HOLDINGS INC.

                                   ARTICLE I

                                     OFFICES

            SECTION 1. REGISTERED OFFICE. The registered office of the
Corporation in the State of Delaware shall be located at the principal place of
business in said state of the corporation or individual acting as the
Corporation's registered agent.

            SECTION 2. OTHER OFFICES. The Corporation may have other offices,
either within or without the State of Delaware, at such place or places as the
Board of Directors may from time to time select.

                                   ARTICLE II

                            MEETINGS OF STOCKHOLDERS

            SECTION 1. ANNUAL MEETINGS. An annual meeting of stockholders for
the election of directors and for the transaction of such other business as may
properly come before the meeting, shall be held at such date, time and place,
either within or without the State of Delaware, as the Board of Directors shall
determine each year.

            SECTION 2. SPECIAL MEETINGS. Special meetings of the stockholders
for any purpose may be called by the Chief Executive Officer or Secretary, or by
the directors, and may be held at any date, time and place, within or without
the State of Delaware, as shall be stated in the notice of meeting.

            SECTION 3. NOTICE OF MEETINGS. Written notice of each annual or
special meeting of the stockholders, stating the place, date and time of the
meeting, and in the case of a special meeting the purpose of such meeting, shall
be given, not less than ten nor more than sixty days before the date of the
meeting, to each stockholder entitled to vote at such meeting, at his address as
it appears on the records of the Corporation.

            SECTION 4. VOTING. Each stockholder shall be entitled to one vote,
in person or by proxy, for each share of stock entitled to vote which is
registered in his name on the record date for the meeting. No proxy shall be
voted after three years from its date unless such proxy


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provides for a longer period. Elections for directors and all other questions
shall be decided by majority vote except as otherwise required by the
Certificate of Incorporation or by law.

            SECTION 5. QUORUM. The holders of a majority of the stock of the
Corporation entitled to vote, present in person or by proxy, shall constitute a
quorum at all meetings of the stockholders, except as otherwise required by law.
If a quorum shall not be present at any meeting, the Chairman of the meeting or
a majority of the holders of the stock of the Corporation entitled to vote who
are present at such meeting, in person or by proxy, shall have the power to
adjourn the meeting to another place, date, or time, without notice other than
announcement at the meeting; provided, however, that if the adjournment is for
more than thirty days, or if after the adjournment a new record date is fixed
for the adjourned meeting, a notice of the adjourned meeting shall be given to
each stockholder of record entitled to vote at the meeting. At any adjourned
meeting, any business may be transacted which might have been transacted at the
original meeting.

            SECTION 6. STOCKHOLDERS LIST. A complete list of stockholders
entitled to vote at any meeting of stockholders, arranged in alphabetical order
for each class of stock and showing the address of each such stockholder and the
number of shares registered in his name, shall be open to the examination of any
such stockholder, for any purpose germane to the meeting, during ordinary
business hours for a period of at least ten days prior to the meeting, either at
a place within the city where the meeting is to be held, which place shall be
specified in the notice of the meeting, or if not so specified, at the place
where the meeting is to be held. The stockholders list shall also be kept at the
place of the meeting during the whole time thereof and shall be open to the
examination of any such stockholder who is present. This list shall
presumptively determine the identity of the stockholders entitled to vote at the
meeting and the number of shares held by each of them.

            SECTION 7. ACTION WITHOUT MEETING. Any action required or permitted
to be taken at any annual or special meeting of stockholders, including, without
limitation, election of directors, may be taken without a meeting, without prior
notice and without a vote, if a consent or consents in writing, setting forth
the action so taken, shall be signed by the holders of outstanding stock having
not less than the minimum number of votes that would be necessary to authorize
or take such action at a meeting at which all shares entitled to vote thereon
were present and voted, and shall be delivered to the Corporation by delivery to
its registered office in the State of Delaware, its principal place of business,
or an officer or agent of the Corporation having custody of the book in which
proceedings of meetings of stockholders are recorded. Delivery made to the
Corporation's registered office shall be by hand or by certified or registered
mail, return receipt requested. Prompt notice of the taking of any action
without a meeting by less than unanimous written consent shall then be given by
the Corporation to those stockholders who have not consented in writing.


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                                  ARTICLE III

                                    DIRECTORS

            SECTION 1. NUMBER AND TERM. The number of directors constituting the
entire Board shall be nine (9). The directors shall be elected to serve until
the next annual meeting of the stockholders and until their respective
successors shall have been elected and qualified.

            Whenever the authorized number of directors is increased between
annual meetings of the stockholders, a majority of the directors then in office,
even though less than a quorum, shall have the power to elect such new directors
for the balance of a term and until their successors are elected and qualified.
Any decrease in the authorized number of directors shall not become effective
until the expiration of the term of the directors then in office unless, at the
time of such decrease, there shall be vacancies on the Board which are being
eliminated by the decrease.

            SECTION 2. RESIGNATIONS. Any director, member of a committee or
officer may resign at any time. Such resignation shall be made in writing, and
shall take effect at the time specified therein, and if no time be specified, at
the time of its receipt by the Chief Executive Officer or Secretary. The
acceptance of a resignation shall not be necessary to make it effective.

            SECTION 3. VACANCIES. If the office of any director, member of a
committee or officer becomes vacant for any reason, the remaining directors in
office, though less than a quorum, by a majority vote, or a sole remaining
director, may elect a successor who shall hold office for the unexpired term and
until his successor shall be elected and qualified.

            SECTION 4. REMOVAL. Any director or directors may be removed with or
without cause at any time by the affirmative vote of the holders of a majority
of all the shares of stock outstanding and entitled to vote.

            SECTION 5. POWERS. The Board of Directors shall exercise all of the
powers of the Corporation except such as are by law, or by the Certificate of
Incorporation or by these Bylaws conferred upon or reserved to the stockholders.

            SECTION 6. MEETINGS. Regular meetings of the Board of Directors may
be held without notice at such dates, times and places as shall be established
from time to time by the Board of Directors and publicized among all directors.
Special meetings of the Board of Directors may be called by the Chief Executive
Officer or Secretary on the request of any director on at least twenty-four
hours' notice of the date, time and place thereof given to each director. Unless
otherwise indicated in the notice thereof, any and all business may be
transacted at a special meeting.

            Members of the Board of Directors, or any committee designated by
the Board of Directors, may participate in a meeting of such Board or committee,
by means of a conference telephone or similar communications equipment that
enables all persons participating in the


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meeting to hear each other, and such participation in a meeting shall constitute
presence in person at the meeting.

            Action by a majority of the directors present at a meeting at which
a quorum is present shall constitute the act of the Board of Directors.

            SECTION 7. QUORUM. A majority of the directors, but in no event less
than three directors, shall constitute a quorum for the transaction of business.
If a quorum shall not be present at any meeting of the Board of Directors, a
majority of those present may adjourn the meeting to another place, date or
time, without further notice (other than announcement at the meeting) or waiver
thereof.

            SECTION 8. COMPENSATION. Directors may receive such compensation for
their services as directors as the Board of Directors shall from time to time
determine by resolution.

            SECTION 9. ACTION WITHOUT MEETING. Any action required or permitted
to be taken at any meeting of the Board of Directors, or of any committee
thereof, may be taken without a meeting, if a written consent thereto is signed
by all members of the Board of Directors, or of such committee, as the case may
be, and such written consent is filed with the minutes of proceedings of the
Board of Directors or such committee.

            SECTION 10. COMMITTEES OF THE BOARD OF DIRECTORS. The Board of
Directors, by a vote of a majority of the whole Board, may from time to time
designate committees of the Board, with such lawfully delegable powers and
duties as it thereby confers, to serve at the pleasure of the Board and shall
elect a director or directors to serve as the member or members of those
committees, designating, if it desires, other directors as alternative members
who may replace any absent or disqualified member at any meeting of the
committee. Any committee so designated may exercise the power and authority of
the Board of Directors to declare a dividend or to authorize the issuance of
stock if the resolution which designates the committee or a supplemental
resolution of the Board of Directors shall so provide. In the absence or
disqualification of any member of any committee and any alternative member in
his place, the member or members of the committee present at the meeting and not
disqualified from voting, whether or not he or they constitute a quorum, may by
unanimous vote appoint another member of the Board of Directors to act at the
meeting in the place of the absent or disqualified member.

                                   ARTICLE IV

                                    OFFICERS

            SECTION 1. GENERALLY. The Board of Directors shall elect a Chief
Executive Officer and a Secretary, each of whom shall hold office until a
successor is elected and qualified or until the earlier resignation or removal
of such officer. The Board of Directors may elect or appoint a President, one or
more Vice Presidents, a Treasurer, one or more Managing Directors (who shall not
be members of the Board of Directors unless otherwise


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properly elected thereto) and such other officers (including Assistant
Secretaries and Assistant Treasurers) and agents as it may deem advisable, who
shall hold their offices for such terms and shall exercise such powers and
perform such duties as the Board of Directors shall determine from time to time.
No officer of the Corporation need be a member of the Board of Directors. Two or
more offices may be held by the same person. Any officer may be removed at any
time, with or without cause, by the Board of Directors.

            SECTION 2. CHIEF EXECUTIVE OFFICER. The Chief Executive Officer
shall preside at all meetings of the stockholders and of the Board of Directors.
Subject to the provisions of these Bylaws and to the direction of the Board of
Directors, he shall have the responsibility for the general management and
control of the affairs and business of the Corporation and shall perform all
duties and have all powers which are commonly incident to the office of Chief
Executive Officer or which from time to time are delegated to him by the Board
of Directors. The Chief Executive Officer shall have the power to sign, in the
name of the Corporation, all authorized stock certificates, contracts,
documents, tax returns, instruments, checks and bonds or other obligations of
the Corporation and shall have general supervision and direction of all of the
other officers and agents of the Corporation.

            SECTION 3. VICE PRESIDENTS. Each Vice President shall have such
powers and shall perform such duties as shall from time to time be designated by
the Board of Directors.

            SECTION 4. TREASURER. The Treasurer, if there be one, shall have the
custody of the corporate funds and securities and shall keep full and accurate
account of receipts and disbursements in books belonging to the Corporation. He
shall deposit all moneys and other valuables in the name and to the credit of
the Corporation in such depositories as may be designated by the Board of
Directors.

            The Treasurer shall disburse the funds of the Corporation as may be
ordered by the Board of Directors, or the Chief Executive Officer, taking proper
vouchers for such disbursements. He shall render to the Chief Executive Officer
and Board of Directors, or whenever they may request it, an account of all his
transactions as Treasurer and of the financial condition of the Corporation. If
required by the Board of Directors, he shall give the Corporation a bond for the
faithful discharge of his duties in such amount and with such surety as the
Board of Directors shall prescribe.

            If there be no Treasurer, the functions and duties of the Treasurer
shall be performed by such other officer or officers of the Corporation as shall
be determined by the Board of Directors or the Chief Executive Officer.

            SECTION 5. SECRETARY. The Secretary shall give, or cause to be
given, notice of all meetings of stockholders and directors, and all other
notices required by law or by these Bylaws, and in case of his absence or
refusal or neglect so to do, any such notice may be given by any person
thereunto directed by the Chief Executive Officer, directors, or stockholders,
upon whose requisition the meeting is called as provided in the Bylaws. He shall
record all the proceedings of the meetings of the Corporation and of the
directors in a book to be kept for that purpose, and shall perform such other
duties as may be assigned to him by the directors or the President. He shall
have the custody of the seal of the Corporation and shall


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affix the same to all instruments requiring it, when authorized by the directors
or the Chief Executive Officer, and attest the same.

            SECTION 6. MANAGING DIRECTORS. Each Managing Director shall have
such powers and shall perform such duties as shall from time to time be
designated by the Board of Directors.

            SECTION 7. ADDITIONAL POWER OF OFFICERS. In addition to the powers
specifically provided in these Bylaws, each officer (including officers other
than those referred to in these Bylaws) shall have such other or additional
authority and perform such duties as the Board of Directors may from time to
time determine.

            SECTION 8. ACTION WITH RESPECT TO SECURITIES OF OTHER CORPORATIONS.
Unless otherwise directed by the Board of Directors, the Chief Executive Officer
shall have the power to vote and otherwise act on behalf of the Corporation, in
person or by proxy, at any meeting of stockholders of or with respect to any
action of stockholders of any other corporation in which this Corporation may
hold securities and otherwise to exercise any and all rights and powers which
this Corporation may possess by reason of its ownership of securities in such
other corporation.

                                   ARTICLE V

                                      STOCK

            SECTION 1. CERTIFICATES OF STOCK. Certificates of stock, signed by
the Chief Executive Officer or a Vice President, and by the Treasurer or the
Secretary or an Assistant Secretary, shall be issued to each stockholder,
certifying the number of shares owned by him in the Corporation. Any of or all
the signatures on the certificates may be facsimiles.

            SECTION 2. LOST, STOLEN OR DESTROYED CERTIFICATES. A new certificate
of stock may be issued in the place of any certificate theretofore issued by the
Corporation, alleged to have been lost, stolen or destroyed, and the directors
may, in their discretion, require the owner of the lost, stolen or destroyed
certificate, or his legal representative, to give the Corporation a bond, in
such sum as they may direct, to indemnify the Corporation against any claim that
may be made against it on account of the alleged loss, theft, or destruction of
any such certificates of the issuance of any such new certificate.

            SECTION 3. TRANSFER OF SHARES. Transfers of stock shall be made only
upon the transfer books of the Corporation kept at an office of the Corporation
or by transfer agents designated to transfer shares of stock of the Corporation.
Upon surrender to the Corporation or its transfer agent or a certificate for
shares duly endorsed or accompanied by proper evidence of succession, assignment
or authority to transfer, the Corporation shall issue or cause its transfer
agent to issue a new certificate to the person entitled thereto, cancel the old
certificate and record the transaction upon its books.


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            SECTION 4. STOCKHOLDERS RECORD DATE. In order that the Corporation
may determine the stockholders entitled to notice of or to vote at any meeting
of stockholders or any adjournment thereof, or to express consent to corporate
action in writing without a meeting, or entitled to receive payment of any
dividend or other distribution or allotment of any rights, or entitled to
exercise any rights in respect of any change, conversion or exchange of stock or
for the purpose of any other lawful action, the Board of Directors may fix, in
advance, a record date, which shall not be more than sixty nor less than ten
days before the date of such meeting, nor more than sixty days prior to any
other action. A determination of stockholders of record entitled to notice of or
to vote at a meeting of stockholders shall apply to any adjournment of the
meeting; provided, however, that the Board of Directors may fix a new record
date for the adjourned meeting.

                                   ARTICLE VI

                                  MISCELLANEOUS

            SECTION 1. DIVIDENDS. Subject to the provisions of the Certificate
of Incorporation, the Board of Directors may, out of funds legally available
therefor at any regular or special meeting, declare dividends upon the capital
stock of the Corporation as and when they deem expedient. Before declaring any
dividend, there may be set apart out of any funds of the Corporation available
for dividends such sum as the directors from time to time in their discretion
deem proper for working capital or as a reserve fund to meet contingencies or
for equalizing dividends or for such other purposes as the directors shall deem
conducive to the interests of the Corporation.

            SECTION 2. SEAL. The corporate seal shall be circular in form and
shall contain the name of the Corporation, the year of its creation and the
words "CORPORATE SEAL" and "DELAWARE". Said seal may be used by causing it or a
facsimile thereof to be impressed or affixed or reproduced or otherwise.

            SECTION 3. FISCAL YEAR. The fiscal year of the Corporation shall be
determined by the Board of Directors.

            SECTION 4. CHECKS. All checks, drafts or other orders for the
payment of money, notes or other evidences of indebtedness issued in the name of
the Corporation shall be signed by such officer or officers, agent or agents of
the Corporation, and in such manner as shall be determined from time to time by
the Board of Directors.

            SECTION 5. NOTICE AND WAIVER OF NOTICE. Whenever any notice is
required to be given, personal notice shall not be necessary unless expressly so
stated, and any notice so required shall be deemed to be sufficient if given by
depositing the same in the United States mail, first class mail (airmail if to
an address outside of the United States), postage prepaid, addressed to the
person entitled thereto at his address as it appears on the records of the
Corporation, in which case such notice shall be deemed given on the day of such
mailing, unless it is notice of a directors' meeting, in which case such notice
shall be deemed given five (5) days after the date of such mailing. Notice may
also be given personally, against receipt, or by


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telecopier, telegram, telex or similar communication and notice so given shall
be deemed given when so delivered personally or when delivered for transmission.

            Stockholders not entitled to vote shall not be entitled to receive
notice of any meetings except as otherwise provided by law.

            Whenever any notice whatsoever is required or permitted to be given
under the provisions of any law, or under the provisions of the Certificate of
Incorporation or these Bylaws, a waiver thereof in writing, signed by the person
or persons entitled to such notice, whether before or after the time such notice
is required to be given, shall be deemed equivalent thereto. A telegram, telex
or similar communication waiving any such notice sent by a person entitled to
notice shall be deemed equivalent to a waiver in writing signed by such person.
Neither the business nor the purpose of any meeting need be specified in any
waiver.

                                  ARTICLE VII

                                   AMENDMENTS

            These Bylaws may be altered, amended or repealed and Bylaws may be
made by the Board of Directors at any meeting or by the stockholders at any
meeting.

                                  ARTICLE VIII

                               INDEMNIFICATION OF
                    DIRECTORS, OFFICERS, EMPLOYEES AND AGENTS

            SECTION 1. INDEMNIFICATION OF DIRECTORS AND OFFICERS. The
Corporation may, by action taken in writing by its Board of Directors in its
sole discretion in a particular case, indemnify and hold harmless any person who
was or is made a party or is threatened to be made a party to any action, suit
or proceeding, whether civil, criminal, administrative or investigative
(hereinafter a "proceeding"), by reason of the fact that he or she or a person
of whom he or she is the legal representative, is or was or has agreed to become
a director or officer of the Corporation, whether the basis of such proceeding
is alleged action in an official capacity as a director or officer or in any
other capacity while serving or having agreed to serve as a director or officer,
to such extent as the Board of Directors of the Corporation, in its sole
discretion, may determine but in no event beyond the extent authorized by the
Delaware General Corporation Law, as the same exists or may hereafter be
amended, against any or all expense, liability and loss (including without
limitation, attorneys' fees, judgments, fines, ERISA excise taxes or penalties
and amounts paid or to be paid in settlement) reasonably incurred or suffered by
such person in connection therewith and, if the action by the Board of Directors
of the Corporation shall so provide, such indemnification shall continue as to a
person who has ceased to serve in the capacity that initially entitled such
person to indemnity under such action and shall inure to the benefit of his or
her heirs, executors and administrators; provided, however, that in no event may
the Corporation indemnify any such person seeking


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indemnification in connection with a proceeding (or part thereof) initiated by
such person unless such proceeding (or part thereof) was specifically authorized
in writing by the Board of Directors of the Corporation and then subject to such
specific limitations and conditions as the action by the Board of Directors of
the Corporation authorizing such indemnification may provide. If the action by
the Board of Directors of the Corporation authorizing indemnification shall so
provide, such indemnification shall include the right to be paid by the
Corporation the expenses incurred in defending any such proceeding in advance of
its final disposition; provided, however, that, if the Delaware General
Corporation Law requires or the action by the Board of Directors of the
Corporation authorizing such indemnification so provides, the payment of such
expenses in advance of the final disposition of a proceeding shall be made only
upon delivery to the Corporation of a bond or similar secured undertaking
acceptable to the Board of Directors of the Corporation, by or on behalf of such
indemnified person, to repay all amounts so advanced if it shall ultimately be
determined that such indemnified person is not entitled to be indemnified under
this Section, the action by the Board of Directors of the Corporation
authorizing indemnification, or otherwise. In any proceeding for which
indemnification is being provided hereunder, the Corporation, at its option by
action by its Board of Directors in its sole discretion, may assume the defense
or prosecution, as applicable, thereof with counsel of the Corporation's
choosing, in which event the indemnified person shall cooperate fully with the
Corporation and counsel so chosen in connection with such proceeding, such
indemnified person may retain counsel of his or her own choosing (but only at
such indemnified person's expense), the Corporation and counsel it has chosen
shall control the proceeding and all settlement negotiations, and such
indemnified person shall not propose or accept any settlement without the
consent of the Corporation. No person for whom indemnification is provided
hereunder may compromise or settle any proceeding for which such indemnification
is provided without the specific written consent of the Board of Directors of
the Corporation.

            SECTION 2. INDEMNIFICATION OF EMPLOYEES AND AGENTS. The Corporation
may, by action taken in writing by its Board of Directors in its sole discretion
in a particular case, provide indemnification to employees and agents of the
Corporation, and to persons who serve at the request of the Corporation as
directors, officers, employees or agents of another corporation or of a
partnership, joint venture, trust or other enterprise, including service with
respect to employee benefit plans, in each case individually or as a group, to
the same extent (or such lesser extent as the action by the Board of Directors
of the Corporation may provide) as the indemnification of directors and officers
permitted by Section 1 of this Article.

            SECTION 3. DEFENSE TO INDEMNIFICATION. It shall be a defense to any
action brought by a person seeking indemnification that, and the Corporation
shall have the right to recover any amounts paid by it to a person on account of
indemnification if, such person has not met the standards of conduct that make
it permissible under the Delaware General Corporation Law for the Corporation to
indemnify such person for the amount sought or paid or such person has failed to
abide by his or her obligations to the Corporation, whether arising by statute,
common law, equity, contract or otherwise.

            SECTION 4. INSURANCE. The Corporation may maintain insurance, at its
expense, to protect itself and any person who is or was serving as a director,
officer, employee or agent of the Corporation or is or was serving at the
request of the Corporation as a director, officer, employee or agent of another
corporation, partnership, joint venture, trust or other


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enterprise against any expense, liability or loss, whether or not the
Corporation would have the power to indemnify such person against such expense,
liability or loss under the Delaware General Corporation Law.

            SECTION 5. INTERESTED DIRECTORS. No director of the Corporation
shall vote on any action by the Board of Directors of the Corporation to provide
indemnification of such director, or of a definite group of persons that
includes such director, with respect to any particular action, suit or
proceeding. In the event that, on account of the provisions of this Section 5,
there shall not be a quorum of the Board of Directors, the Corporation may
provide such indemnification only by action of its stockholders.


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