<PAGE>   1
                                                                    EXHIBIT 4.13



                          REGISTRATION RIGHTS AGREEMENT

                                      among

                           OPTIMARK TECHNOLOGIES, INC.

                                       and

                           THE HOLDERS OF ITS SERIES D

                                   CONVERTIBLE

                                 PREFERRED STOCK



                                - July 30, 1999 -



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                                TABLE OF CONTENTS

                                                                           PAGE
                                                                           ----


1.    Definitions.............................................................1


2.    General; Securities Subject to this Agreement...........................3

      (a)         Grant of Rights.............................................3
      (b)         Registrable Securities......................................3
      (c)         Holders of Registrable Securities...........................3

3.    Piggy-Back Registration.................................................4

      (a)         Piggy-Back Rights...........................................4
      (b)         Expenses....................................................4

4.    Holdback Agreements.....................................................5

      (a)         Restrictions on Public Sale by Designated Holders...........5
      (b)         Restrictions on Public Sale by the Company..................5

5.    Registration Procedures.................................................5

      (a)         Obligations of the Company..................................5
      (b)         Seller Information..........................................8
      (c)         Notice to Discontinue.......................................8
      (d)         Registration Expenses.......................................9

6.    Indemnification; Contribution...........................................9

      (a)         Indemnification by the Company..............................9
      (b)         Indemnification by Designated Holders.......................9
      (c)         Procedures.................................................10
      (d)         Contribution...............................................10
      (e)         Limitations................................................11

7.    Rule 144...............................................................11


8.    Miscellaneous..........................................................11

      (a)         Recapitalizations, Exchanges, etc..........................11
      (b)         No Inconsistent Agreements.................................11
      (c)         Remedies...................................................12
      (d)         Amendments and Waivers.....................................12
      (e)         Notices....................................................12
      (f)         Successors and Assigns; Third Party Beneficiaries..........13
      (g)         Counterparts...............................................13
      (h)         Headings...................................................13
      (i)         Governing Law..............................................13
      (j)         Severability...............................................13
      (k)         Entire Agreement...........................................13
      (l)         Further Assurances.........................................14

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        REGISTRATION RIGHTS AGREEMENT, dated July 30, 1999 (this "Agreement"),
among OptiMark Technologies, Inc., a Delaware corporation (the "Company"), and
the purchaser(s) ("Purchasers") of the Company's Series D Convertible Preferred
Stock ("Series D Stock") listed on Schedule I hereto.

        This Agreement is made in connection with Series D Stock Purchase
Agreements (the "Stock Purchase Agreements"), between the Company and the
Purchaser(s) pursuant to which the Company has agreed to issue and sell Series D
Stock. Each share of Series D Stock is convertible into one (1) share of Common
Stock, subject to potential adjustments. In order to induce the Purchaser(s) to
purchase Series D Stock, and for other good and valuable consideration, the
receipt and adequacy of which are hereby acknowledged, the Company has agreed to
grant registration rights with respect to the Registrable Securities (as
hereinafter defined) as set forth in this Agreement.

        The parties hereby agree as follows:

        1.      Definitions. As used in this Agreement in addition to other
capitalized terms defined elsewhere herein, the following terms shall have the
meanings indicated:

                "Act" means the Securities Act of 1933, as amended, and the
rules and regulations promulgated thereunder.

                "Affiliate" shall mean any Person who is an "affiliate" of
another designated Person, as defined in Rule l2b-2 of the General Rules and
Regulations under the Exchange Act.

                "Common Stock" means the common stock, par value $.01 per share,
of the Company or any other equity securities of the Company into which such
securities are converted, reclassified, reconstituted or exchanged.

                "Company" has the meaning assigned to such term in the recital
to this Agreement.

                "Company Underwriter" has the meaning assigned such term in
Section 3(a) below.

                "Damages" has the meaning assigned to such term in Section 6(a)
below.

                "Designated Holder" means each Purchaser and any transferee of
any Purchaser to whom Registrable Securities have been transferred in accordance
with the provisions of this Agreement , other than a transferee to whom such
securities have been transferred pursuant to a Registration Statement or Rule
144 or Regulation S under the Act.

                "Exchange Act" means the Securities Exchange Act of 1934 as
amended, and the rules and regulations promulgated thereunder.

                "Holders' Counsel" has the meaning assigned such term in Section
5(a)(i) below.

                "Indemnified Party" has the meaning assigned such term in
Section 6(c) below.



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                "Indemnifying Party" has the meaning assigned such term in
Section 6(c) below.

                "Inspector" has the meaning assigned such term in Section
5(a)(viii) below.

                "IPO Effectiveness Date" means the date upon which the Company
commences an initial offer for sale of shares of Common Stock pursuant to an
effective Registration Statement.

                "NASD" means the National Association of Securities Dealers,
Inc.

                "Nasdaq Warrant" means the Warrant Agreement dated September 1,
1998 pursuant to which The Nasdaq Stock Market, Inc. has the right to purchase
from the Company up to 11,250,000 shares of voting Common Stock at exercise
prices ranging from $3.00 to $7.00 per share, subject to potential adjustment as
provided therein.

                "Other Rights Holders" means (i) the holders of the Series A
Stock, (ii) the holders of the Series B Stock, (iii) the holders of the Series C
Stock, (iv) the holder of the Nasdaq Warrant, and (iv) any other Persons holding
registration rights with respect to Common Stock whose registration rights have
not expressly been made junior to the registration rights of the Designated
Holders hereunder.

                "Person" means any individual, firm, corporation, partnership,
limited liability company, trust, incorporated or unincorporated association,
joint venture, joint stock company, limited liability company, government (or an
agency or political subdivision thereof) or other entity of any kind, and shall
include any successor (by merger or otherwise) of such entity.

                "Purchaser(s)" has the meaning assigned to such term in the
recital to this Agreement.

                "Records" has the meaning assigned such term in Section
5(a)(viii) below.

                "Registrable Securities" means each of the following: (a) any
and all shares of Common Stock owned by the Designated Holders and issued or
issuable upon conversion of shares of Series D Stock, (b) any other shares of
Common Stock acquired or owned by any of the Designated Holders prior to the IPO
Effectiveness Date, and (c) any shares of Common Stock issued or issuable to any
of the Designated Holders with respect to shares of Common Stock or shares of
Series D Stock by way of stock dividend or stock split or in connection with a
combination of shares, recapitalization, merger, consolidation or other
reorganization or otherwise, and shares of Common Stock issuable upon
conversion, exercise or exchange thereof.

                "Registration Expenses" has the meaning set forth in Section
5(d) below.

                "Registration Statement" means a Registration Statement filed by
the Company pursuant to the Act.

                "SEC" means the Securities and Exchange Commission or any
successor agency then having jurisdiction to enforce the Act.


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                "Series A Stock" means the Company's Series A Convertible
Participating Preferred Stock, $.01 par value per share.

                "Series B Stock" means the Company's Series B Convertible
Participating Preferred Stock, $.01 par value per share.

                "Series C Stock" means the Company's Series C Convertible
Preferred Stock, $.01 par value per share.

                "Series D Stock" has the meaning assigned to such term in the
recital to this Agreement.

                "Stock Purchase Agreement" has the meaning assigned such term in
the recital to this Agreement.

        2.      General; Securities Subject to this Agreement Grant of Rights.
The Company hereby grants registration rights to the Purchasers upon the terms
and conditions set forth in this Agreement.

                (b)     Registrable Securities. For purposes of this Agreement,
Registrable Securities will cease to be Registrable Securities when (i) a
Registration Statement covering such Registrable Securities has been declared
effective by the SEC, and such Registrable Securities have been disposed of
pursuant to such effective Registration Statement, (ii) the entire amount of
such Registrable Securities proposed to be sold in a single sale are or, in the
opinion of counsel satisfactory to the Company and the Designated Holder, each
in their reasonable judgment, may be distributed to the public without any
limitation as to volume pursuant to Rule 144 (or any successor provision then in
effect) under the Act, or (iii) such Registrable Securities are sold,
distributed or proposed to be sold or distributed by a Person not entitled to
the registration rights granted by this Agreement.

                (c)     Holders of Registrable Securities. A Person is deemed to
be a holder of Registrable Securities whenever such Person owns of record
Registrable Securities. If the Company receives conflicting instructions,
notices or elections from two or more Persons with respect to the same
Registrable Securities, the Company may act upon the basis of the instructions,
notice or election received from the record owner of such Registrable
Securities.

        3.      Piggy-Back Registration Piggy-Back Rights. At any time after the
IPO Effectiveness Date, if either (I) the Company proposes to file a
Registration Statement with respect to an offering by the Company of Common
Stock for its own account (other than a Registration Statement on Form S-4 or
S-8 or any successors thereto) (a "Company Registration"), or (II) the Company
is required to file a Registration Statement upon demand by and for the account
of any "Initiating Holders", as defined and provided in Section 3 of the
Registration Rights Agreement dated August 27, 1996, as amended, among the
Company and the holders of its Series A Stock (a "Demand Registration"), then
the Company shall give written notice of such proposed filing to each of the
Designated Holders of



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Registrable Securities at least thirty (30) days before the anticipated filing
date, and such notice shall describe the proposed registration and distribution
and offer such Designated Holders the opportunity to register such number of
Registrable Securities as each such holder may request. The Company shall, and
shall use reasonable efforts to cause the managing underwriter(s) of a proposed
underwritten offering (the "Company Underwriter") to, permit the Designated
Holders of Registrable Securities who have requested in writing to participate
in the registration for such offering to include such Registrable Securities in
such offering on the same terms and conditions as the securities of the Company
or the Initiating Holders included therein. In connection with any offering
under this Section 3(a) involving an underwriting, the Company shall not be
required to include any Registrable Securities in such underwriting unless the
holders thereof accept the terms of the underwriting as agreed upon between the
Company and the Company Underwriter, and then only in such quantity as will
not, in the opinion of the Company Underwriter, jeopardize the success of the
offering by the Company. If in the written opinion of the Company Underwriter
the registration of all or part of the Registrable Securities which the
Designated Holders have requested to be included would materially adversely
affect such public offering, then the Company shall include in the
underwriting, to the extent of the amount that the Company Underwriter believes
may be sold without causing such adverse effect, (A) in connection with a
Company Registration, first, all of the securities to be offered for the
account of the Company; and second, as a group, (i) the Registrable Securities
requested by Designated Holders to be sold in the offering, and (ii) the Common
Stock requested by Other Rights Holders to be sold in the offering, pro rata
based upon the number of shares of Registrable Securities/Common Stock owned by
such Persons; or (B) in connection with a Demand Registration, first, as a
group, (i) the Registrable Securities requested by Designated Holders to be
sold in the offering, and (ii) the Common Stock requested by Other Rights
Holders to be sold in the offering, pro rata based upon the number of shares of
Registrable Securities/Common Stock owned by such Persons, and second, all of
the securities to be offered for the account of the Company.

                (b)     Expenses. The Company shall bear all Registration
Expenses (other than underwriting discounts and commissions) in connection with
any registration pursuant to this Section 3; provided, however, that each
Designated Holder participating in such registration shall bear the costs of its
own legal counsel, if any.

        4.      Holdback Agreements Restrictions on Public Sale by Designated
Holders. Each Designated Holder of Registrable Securities agrees not to effect
any public sale or distribution of any Registrable Securities or of any
securities convertible into or exchangeable or exercisable for such Registrable
Securities, including a sale pursuant to Rule 144 under the Act, during the
180-day period beginning on the effective date of any Registration Statement
(except as part of such registration), if and to the extent requested by the
Company in the case of a nonunderwritten public offering or if and to the extent
requested by the Company Underwriter in the case of an underwritten public
offering.

        (b)     Restrictions on Public Sale by the Company. The Company agrees
not to effect any public sale or distribution of any of its Common Stock, or any
securities convertible into or exchangeable or exercisable for such securities
(except pursuant to registrations on Form S-4 or



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S-8 or any successor thereto), during the period beginning on the effective date
of any Registration Statement (except as part of such registration) in which the
Designated Holders of Registrable Securities are participating and ending on the
earlier of (i) the date on which all Registrable Securities registered on such
Registration Statement are sold and (ii) three (3) months after the effective
date of such Registration Statement.

        5.      Registration Procedures Obligations of the Company. Whenever
registration of Registrable Securities has been requested pursuant to Section 3
of this Agreement, the Company shall use its reasonable efforts to effect the
registration and sale of such Registrable Securities in accordance with the
intended method of distribution thereof as quickly as practicable, and in
connection with any such request, the Company shall, as expeditiously as
possible:

                        (i)     use its reasonable efforts to prepare and file
with the SEC a Registration Statement on any form for which the Company then
qualifies or which counsel for the Company shall deem appropriate and which form
shall be available for the sale of the Common Stock and such Registrable
Securities in accordance with the intended method of distribution thereof, and
use its reasonable efforts to cause such Registration Statement to become
effective; provided, however, that (x) before filing a Registration Statement or
prospectus or any amendments or supplements thereto, the Company shall provide
counsel selected by the Designated Holders holding a majority of the Registrable
Securities being registered in such registration ("Holders' Counsel") and any
other Inspector (as hereinafter defined) with an adequate and appropriate
opportunity to participate in the preparation of such Registration Statement and
each prospectus included therein (and each amendment or supplement thereto) to
be filed with the SEC, which documents shall be subject to the review of
Holders' Counsel, and (y) the Company shall notify the Holders' Counsel and each
seller of Registrable Securities of any stop order issued or threatened by the
SEC and take all reasonable action required to prevent the entry of such stop
order or to remove it if entered;

                        (ii)    prepare and file with the SEC such amendments
and supplements to such Registration Statement and the prospectus used in
connection therewith as may be necessary to keep such Registration Statement
effective for the lesser of (x) three (3) months and (y) such shorter period
which will terminate when all Registrable Securities covered by such
Registration Statement have been sold, and comply with the provisions of the Act
with respect to the disposition of all securities covered by such Registration
Statement during such period in accordance with the intended methods of
disposition by the sellers thereof set forth in such Registration Statement;

                        (iii)   as soon as reasonably possible, furnish to each
seller of Registrable Securities, prior to filing a Registration Statement,
copies of such Registration Statement as is proposed to be filed, and thereafter
such number of copies of such Registration Statement, each amendment and
supplement thereto (in each case including all exhibits thereto), the prospectus
included in such Registration Statement (including each preliminary prospectus)
and such other documents as each such seller may reasonably request in order to
facilitate the disposition of the Registrable Securities owned by such seller;



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                        (iv)    use its reasonable efforts to register or
qualify such Registrable Securities under such other securities or "blue sky"
laws of such jurisdictions as any seller of Registrable Securities may
reasonably request, and to continue such qualification in effect in such
jurisdiction for the lesser of (x) three (3) months and (y) such shorter period
which will terminate when all Registrable Securities covered by such
Registration Statement have been sold, and do any and all other acts and things
which may be reasonably necessary or advisable to enable any such seller to
consummate the disposition in such jurisdictions of the Registrable Securities
owned by such seller; provided, however, that the Company shall not be required
to (x) qualify generally to do business in any jurisdiction where it would not
otherwise be required to qualify but for this Section 5(a)(iv), (y) subject
itself to taxation in any such jurisdiction or (z) consent to general service of
process in any such jurisdiction;

                        (v)     use its reasonable efforts to cause the
Registrable Securities covered by such Registration Statement to be registered
with or approved by such other governmental agencies or authorities as may be
necessary by virtue of the business and operations of the Company to enable the
seller or sellers of Registrable Securities to consummate the disposition of
such Registrable Securities;

                        (vi)    upon discovery that, or upon the happening of
any event as a result of which, the prospectus included in a Registration
Statement covering Registrable Securities contains an untrue statement of a
material fact or omits to state any material fact required to be stated therein
or necessary to make the statements therein not misleading in light of the
circumstances under which they were made, (x) promptly prepare a supplement or
amendment to such prospectus and furnish to each seller of Registrable
Securities a reasonable number of copies of a supplement to or an amendment of
such prospectus as may be necessary so that, after delivery to the purchasers of
such Registrable Securities, such prospectus shall not contain an untrue
statement of a material fact or omit to state any material fact required to be
stated therein or necessary to make the statements therein not misleading in
light of the circumstances under which they were made and (y) immediately prior
to the preparation of such amendment or supplement to such prospectus, notify
each seller of Registrable Securities of the anticipated preparation thereof;

                        (vii)   enter into and perform customary agreements
(including an underwriting agreement in customary form with the Company
Underwriter, if any) and take such other actions as are prudent and reasonably
required in order to expedite or facilitate the disposition of such Registrable
Securities;

                        (viii)  make available for inspection by any seller of
Registrable Securities, any managing underwriter participating in any
disposition pursuant to such Registration Statement, Holders' Counsel and any
attorney, accountant or other agent retained by any such seller or any managing
underwriter (each, an "Inspector" and collectively, the "Inspectors"), all
financial and other records, pertinent corporate documents and properties of the
Company and its subsidiaries (collectively, the "Records") as shall be
reasonably necessary to enable them to exercise their due diligence
responsibility, and cause the Company's and its subsidiaries' officers,
directors and employees, and the independent public accountants of the Company,
to supply all information



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reasonably requested by any such Inspector in connection with such Registration
Statement. Records that the Company determines, in good faith, to be
confidential and which it notifies the Inspectors are confidential shall not be
disclosed by the Inspectors unless (x) the disclosure of such Records is
necessary to avoid or correct a misstatement or omission in the Registration
Statement, (y) the release of such Records is ordered pursuant to a subpoena or
other order from a court of competent jurisdiction or (z) the information in
such Records was known to the Inspectors on a non-confidential basis prior to
its disclosure by the Company or has been made generally available to the
public. Each seller of Registrable Securities agrees that it shall, upon
learning that disclosure of such Records is sought in a court of competent
jurisdiction, give notice to the Company and allow the Company, at the Company's
expense, to undertake appropriate action to prevent disclosure of the Records
deemed confidential;

                        (ix)    if such sale is pursuant to an underwritten
offering, use its reasonable efforts to obtain a "cold comfort" letter from the
Company's independent public accountants in customary form and covering such
matters of the type customarily covered by "cold comfort" letters as Holders'
Counsel or the managing underwriter reasonably request;

                        (x)     use its reasonable efforts to furnish, at the
request of any seller of Registrable Securities on the date such securities are
delivered to the underwriters for sale pursuant to such registration or, if such
securities are not being sold through underwriters, on the date the Registration
Statement with respect to such securities becomes effective, an opinion, dated
such date, of counsel representing the Company for the purposes of such
registration, addressed to the underwriters, if any, and to the seller making
such request, covering such legal matters with respect to the registration in
respect of which such opinion is being given as such seller may reasonably
request and are customarily included in such opinions;

                        (xi)    otherwise use its reasonable efforts to comply
with all applicable rules and regulations of the SEC, and make available to its
security holders, as soon as reasonably practicable but no later than fifteen
(15) months after the effective date of the Registration Statement, an earnings
statement covering a period of twelve (12) months beginning after the effective
date of the Registration Statement, in a manner which satisfies the provisions
of Section 11(a) of the Act and Rule 158 thereunder;

                        (xii)   cause all such Registrable Securities to be
listed on each securities exchange on which similar securities issued by the
Company are then listed, provided that the applicable listing requirements are
satisfied;

                        (xiii)  cooperate with each seller of Registrable
Securities and each underwriter participating in the disposition of such
Registrable Securities and their respective counsel in connection with any
filings required to be made with the NASD; and

                        (xiv)   use reasonable efforts to take all other steps
necessary to effect the registration of the Registrable Securities contemplated
hereby.



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                (b)     Seller Information. The Company may require each seller
of Registrable Securities as to which any registration is being effected to
furnish to the Company such information regarding the distribution of such
securities as the Company may from time to time reasonably request in writing.

                (c)     Notice to Discontinue. Each Designated Holder of
Registrable Securities agrees that, upon receipt of any notice from the Company
of the happening of any event of the kind described in Section 5(a)(vi), such
Designated Holder shall forthwith discontinue disposition of Registrable
Securities pursuant to the Registration Statement covering such Registrable
Securities until such Designated Holder's receipt of the copies of the
supplemented or amended prospectus contemplated by Section 5(a)(vi) and, if so
directed by the Company, such Designated Holder shall deliver to the Company (at
the Company's expense) all copies, other than permanent file copies then in such
Designated Holder's possession, of the prospectus covering such Registrable
Securities which is current at the time of receipt of such notice. If the
Company shall give any such notice, the Company shall extend the period during
which such Registration Statement shall be maintained effective pursuant to this
Agreement (including, without limitation, the period referred to in Section
5(a)(ii)) by the number of days during the period from and including the date of
the giving of such notice pursuant to Section 5(a)(vi) to and including the date
when the Designated Holder shall have received the copies of the supplemented or
amended prospectus contemplated by and meeting the requirements of Section
5(a)(vi).

                (d)     Registration Expenses. The Company shall pay all
expenses (other than as set forth in Section 3(b)) arising from or incident to
the performance of, or compliance with, this Agreement, including, without
limitation, (i) SEC, stock exchange and NASD registration and filing fees, (ii)
all fees and expenses incurred in complying with securities or "blue sky" laws
(including reasonable fees, charges and disbursements of counsel in connection
with "blue sky" qualifications of the Registrable Securities), (iii) all
printing, messenger and delivery expenses, (iv) the fees, charges and
disbursements of counsel to the Company and of its independent public
accountants and any other accounting and legal fees, charges and expenses
incurred by the Company (including, without limitation, any expenses arising
from any special audits incident to or required by any registration or
qualification) and (v) any liability insurance or other premiums for insurance
obtained in connection with any registration pursuant to the terms of this
Agreement, regardless of whether such Registration Statement is declared
effective. All of the expenses described in this Section 5(d) are referred to
herein as "Registration Expenses."

        6.      Indemnification; Contribution Indemnification by the Company.
The Company agrees to indemnify and hold harmless, to the fullest extent
permitted by law, each Designated Holder, its officers, directors, trustees,
partners, members, employees, advisors and agents and each Person who controls
(within the meaning of the Act or the Exchange Act) such Designated Holder from
and against any and all losses, claims, damages, liabilities and expenses,
including reasonable costs of investigation (generally, "Damages"), arising out
of or based upon any untrue, or allegedly



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<PAGE>   11

untrue, statement of a material fact contained in any Registration Statement,
prospectus or preliminary prospectus or notification or offering circular (as
amended or supplemented if the Company shall have furnished any amendments or
supplements thereto) or arising out of or based upon any omission or alleged
omission to state therein a material fact required to be stated therein or
necessary to make the statements therein not misleading, except insofar as the
same are caused by or contained in any information concerning such Designated
Holder furnished in writing to the Company by such Designated Holder expressly
for use therein. The Company shall also provide customary indemnities to any
underwriters of the Registrable Securities, their officers, directors and
employees and each Person who controls such underwriters (within the meaning of
the Act and the Exchange Act) to the same extent as provided above with respect
to the indemnification of the Designated Holders of Registrable Securities.

                (b)     Indemnification by Designated Holders. In connection
with any Registration Statement in which a Designated Holder is participating
pursuant to Section 3 hereof, each such Designated Holder shall furnish to the
Company in writing such information with respect to such Designated Holder as
the Company may reasonably request or as may be required by law for use in
connection with any such Registration Statement or prospectus, and each
Designated Holder agrees to indemnify and hold harmless, to the fullest extent
permitted by law, the Company, any underwriter retained by the Company and their
respective directors, officers, employees and each Person who controls the
Company or such underwriter (within the meaning of the Act and the Exchange Act)
to the same extent as the foregoing indemnity from the Company to the Designated
Holders, but only with respect to any such information with respect to such
Designated Holder furnished in writing to the Company by such Designated Holder
expressly for use therein.

                (c)     Procedures. Any Person entitled to indemnification
hereunder (the "Indemnified Party") agrees to give prompt written notice to the
indemnifying party (the "Indemnifying Party") after the receipt by the
Indemnified Party of any written notice of the commencement of any action, suit,
proceeding or investigation or threat thereof made in writing for which the
Indemnified Party intends to claim indemnification or contribution pursuant to
this Agreement; provided, however, that the failure so to notify the
Indemnifying Party shall not relieve the Indemnifying Party of any liability
that it may have to the Indemnified Party hereunder. If notice of commencement
of any such action is given to the Indemnifying Party as above provided, the
Indemnifying Party shall be entitled to participate in and, to the extent it may
wish, jointly with any other Indemnifying Party similarly notified, to assume
the defense of such action at its own expense, with counsel chosen by it and
satisfactory to such Indemnified Party. The Indemnified Party shall have the
right to employ separate counsel in any such action and participate in the
defense thereof, but the fees and expenses of such counsel (other than
reasonable costs of investigation) shall be paid by the Indemnified Party unless
(i) the Indemnifying Party agrees to pay the same, (ii) the Indemnifying Party
fails to assume the defense of such action with counsel satisfactory to the
Indemnified Party in its reasonable judgment or (iii) the named parties to any
such action (including any impleaded parties) have been advised by such counsel
that either (x) representation of such Indemnified Party and the Indemnifying
Party by the same counsel would be inappropriate under applicable standards of
professional conduct or (y) there may be one or more legal defenses available to
it which are different from or additional to and in conflict with those
available to the



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<PAGE>   12

Indemnifying Party and in such event, the Indemnifying Party shall pay the fees
and expenses of counsel to the Indemnified Party only to the extent that such
separate counsel is necessary under such applicable standards of professional
conduct in the case of the foregoing clause (x) or to the extent necessary to
avoid any conflict in the case of the foregoing clause (y). In either of such
cases, the Indemnifying Party shall not have the right to assume the defense of
such action on behalf of such Indemnified Party. No Indemnifying Party shall be
liable for any settlement entered into without its written consent, which
consent shall not be unreasonably withheld.

                (d)     Contribution. If the indemnification provided for in
this Section 6 from the Indemnifying Party is unavailable to an Indemnified
Party hereunder in respect of any Damages referred to therein, then the
Indemnifying Party, in lieu of indemnifying such Indemnified Party, shall
contribute to the amount of Damages paid or payable by such Indemnified Party in
such proportion as is appropriate to reflect the relative fault of the
Indemnifying Party and Indemnified Party in connection with the actions which
resulted in such Damages, as well as any other relevant equitable
considerations. The relative faults of such Indemnifying Party and Indemnified
Party shall be determined by reference to, among other things, whether any
action in question, including any untrue or alleged untrue statement of a
material fact or omission or alleged omission to state a material fact, has been
made by, or relates to information supplied by, such Indemnifying Party or
Indemnified Party, and the parties' relative intent, knowledge, access to
information and opportunity to correct or prevent such action. The parties
hereto agree that it would not be just and equitable if contribution pursuant to
this Section 6(d) were determined by pro rata allocation or by any other method
of allocation which does not take account of the equitable considerations
referred to in this paragraph.

                (e)     Limitations. No Person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Act) shall be
entitled to indemnification or contribution from any Person. Notwithstanding
anything to the contrary provided above, the total amount of Damages subject to
indemnification or contribution by any Designated Holder under this Section 6
shall not exceed the net proceeds received by such Designated Holder in the
offering to which the registration statement or prospectus relates.

        7.      Rule 144. From and after the IPO Effectiveness Date, the Company
covenants that it shall file any reports required to be filed by it under the
Exchange Act and that it shall take such further action as each Designated
Holder of Registrable Securities may reasonably request (including providing any
information necessary to comply with Rules 144 and 144A under the Act), all to
the extent required from time to time to enable such Designated Holder to sell
Registrable Securities without registration under the Act within the limitation
of the exemptions provided by (a) Rule 144 under the Act, as such rules may be
amended from time to time, or (b) any similar rules or regulations hereafter
adopted by the SEC. The Company shall, upon the request of any Designated Holder
of Registrable Securities, deliver to such Designated Holder a written statement
as to whether it has complied with such requirements.

        8.      Miscellaneous Recapitalizations, Exchanges, etc. The provisions
of this Agreement shall apply, to the full extent set forth herein with respect
to (i) the shares of Common Stock and



                                      -10-

<PAGE>   13

(ii) to any and all equity securities of the Company or any successor or assign
of the Company (whether by merger, consolidation, sale of assets or otherwise)
which may be issued in respect of, in conversion of, in exchange for or in
substitution of, the Common Stock, and shall be appropriately adjusted for any
stock dividends, splits, reverse splits, combinations, recapitalizations and the
like occurring after the date hereof. The Company shall cause any successor or
assign (whether by sale, merger or otherwise) to enter into a new registration
rights agreement with the Designated Holders on terms substantially the same as
this Agreement as a condition of any such transaction.

                (b)     No Inconsistent Agreements. The Company shall not enter
into any agreement with respect to its securities that is inconsistent with the
rights granted to the Designated Holders in this Agreement or grant any
additional registration rights to any Person or with respect to any securities
which are not Registrable Securities which are prior in right to or inconsistent
with the rights granted in this Agreement.

                (c)     Remedies. The Designated Holders, in addition to being
entitled to exercise all rights granted by law, including recovery of damages,
shall be entitled to specific performance of their rights under this Agreement.
The Company agrees that monetary damages would not be adequate compensation for
any loss incurred by reason of a breach by it of the provisions of this
Agreement and hereby agrees to waive in any action for specific performance the
defense that a remedy at law would be adequate.

                (d)     Amendments and Waivers. Except as otherwise provided
herein, the provisions of this Agreement may not be amended, modified or
supplemented, and waivers or consents to departures from the provisions hereof
may not be given unless consented to in writing by (i) the Company and (ii)
Designated Holders owning at least 75% of the Registrable Securities. Any such
written consent shall be binding upon the Company and all of the Designated
Holders.

                (e)     Notices. All notices, demands and other communications
provided for or permitted hereunder shall be made in writing and shall be made
by registered or certified first-class mail, return receipt requested, courier
service, overnight mail or personal delivery as follows:

                        (i)     if to the Company:

                                OptiMark Technologies, Inc.
                                10 Exchange Place, 12th Floor
                                Jersey City, New Jersey 07302

                                Telecopy:  (201) 946-9435
                                Attention: Chief Executive Officer

                                with a copy to:

                                OptiMark Technologies, Inc.
                                10 Exchange Place, 12th Floor
                                Jersey City, New Jersey 07302



<PAGE>   14
                                Telecopy:  (201) 946-9435
                                Attention:  General Counsel

                        (ii)    if to any Purchaser:

                                To the address of such Purchaser shown on
                                Schedule I hereto, or to any other address of
                                which a Purchaser may give notice to the Company
                                pursuant to this paragraph (e)

        All such notices and communications shall be deemed to have been duly
given when delivered by hand, if personally delivered; when delivered by courier
or overnight mail, if delivered by commercial courier service or overnight mail;
and five (5) Business Days after being deposited in the mail, postage prepaid,
if mailed.

                (f)     Successors and Assigns; Third Party Beneficiaries. This
Agreement shall inure to the benefit of and be binding upon the successors and
assigns of each of the parties hereto. No Person other than the parties hereto
and their successors and permitted assigns is intended to be a beneficiary of
any of the rights granted hereunder.

                (g)     Counterparts. This Agreement may be executed in any
number of counterparts and by the parties hereto in separate counterparts, each
of which when so executed shall be deemed to be an original and all of which
taken together shall constitute one and the same agreement.

                (h)     Headings. The headings in this Agreement are for
convenience of reference only and shall not limit or otherwise affect the
meaning hereof.

                (i)     GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF DELAWARE WITHOUT REGARD TO
THE PRINCIPLES OF CONFLICTS OF LAW THEREOF.

                (j)     Severability. If any one or more of the provisions
contained herein, or the application thereof in any circumstances, is held
invalid, illegal or unenforceable in any respect for any reason, the validity,
legality and enforceability of any such provision in every other respect and of
the remaining provisions hereof shall not be in any way impaired, it being
intended that all of the rights and privileges of the Designated Holders shall
be enforceable to the fullest extent permitted by law.

                (k)     Entire Agreement. This Agreement is intended by the
parties as a final expression of their agreement and intended to be a complete
and exclusive statement of the agreement and understanding of the parties hereto
in respect of the subject matter contained herein. There are no restrictions,
promises, warranties or undertakings, other than those set forth or referred to
herein and in the Stock Purchase Agreement. This Agreement supersedes all prior
agreements and understandings between the parties with respect to such subject
matter.



                                      -12-

<PAGE>   15

                (l)     Further Assurances. Each of the parties shall execute
such documents and perform such further acts as may be reasonably required or
desirable to carry out or to perform the provisions of this Agreement.

        IN WITNESS WHEREOF, the undersigned have executed, or have caused to be
executed, this Agreement on the date first written above.

                                         COMPANY:
                                         --------

                                         OPTIMARK TECHNOLOGIES, INC.

                                         By:  /s/  Phillip J. Riese
                                         Chief Executive Officer


                                         PURCHASERS:
                                         -----------

                                         See attached signature pages


                                      -13-

<PAGE>   16



                                 Signature Page
             (to Registration Rights Agreement dated July 30, 1999)
                                           Purchaser: BancBoston Capital Inc.

                                           By:  /s/  Mary J. Reilly
                                           Director



<PAGE>   17



                                   Schedule I
              (to Registration Rights Agreement dated July 30, 1999)



                                                                 NUMBER OF
                                                  EFFECTIVE      SHARES OF
                                                   DATE OF    SERIES D STOCK
CERT. NO.   NAME AND ADDRESS OF PURCHASER         PURCHASE      PURCHASED
---------   -----------------------------         --------      ---------

OTD-1        BancBoston Capital Inc.              07/30/99       250,000
             175 Federal Street
             Boston, Massachusetts 02110
             Attention:  Mary Reilly