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                                                                   EXHIBIT 10.31







                              TRADINGDYNAMICS, INC.


                                 1999 STOCK PLAN


                             ADOPTED DECEMBER, 1999

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                                TABLE OF CONTENTS


                                                                        Page No.
                                                                        --------


SECTION 1.  ESTABLISHMENT AND PURPOSE..........................................1


SECTION 2.  ADMINISTRATION.....................................................1

   (a)  Committees of the Board of Directors...................................1
   (b)  Authority of the Board of Directors....................................1

SECTION 3.  ELIGIBILITY........................................................1

   (a)  General Rule...........................................................1
   (b)  Ten-Percent Shareholders...............................................1

SECTION 4.  STOCK SUBJECT TO PLAN..............................................2

   (a)  Basic Limitation.......................................................2
   (b)  Additional Shares......................................................2

SECTION 5.  TERMS AND CONDITIONS OF AWARDS OR SALES............................2

   (a)  Stock Purchase Agreement...............................................2
   (b)  Duration of Offers and Nontransferability of Rights....................2
   (c)  Purchase Price.........................................................2
   (d)  Withholding Taxes......................................................2
   (e)  Restrictions on Transfer of Shares and Minimum Vesting.................2
   (f)  Accelerated Vesting....................................................3

SECTION 6.  TERMS AND CONDITIONS OF OPTIONS....................................3

   (a)  Stock Option Agreement.................................................3
   (b)  Number of Shares.......................................................3
   (c)  Exercise Price.........................................................3
   (d)  Withholding Taxes......................................................3
   (e)  Exercisability.........................................................3
   (f)  Accelerated Exercisability.............................................3
   (g)  Basic Term.............................................................4
   (h)  Nontransferability.....................................................4
   (i)  Termination of Service (Except by Death)...............................4
   (j)  Leaves of Absence......................................................4
   (k)  Death of Optionee......................................................5
   (l)  No Rights as a Shareholder.............................................5
   (m)  Modification, Extension and Assumption of Options......................5
   (n)  Restrictions on Transfer of Shares and Minimum Vesting.................5
   (o)  Accelerated Vesting....................................................5


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SECTION 7.  PAYMENT FOR SHARES.................................................6

   (a)  General Rule...........................................................6
   (b)  Surrender of Stock.....................................................6
   (c)  Services Rendered......................................................6
   (d)  Promissory Note........................................................6
   (e)  Exercise/Sale..........................................................6
   (f)  Exercise/Pledge........................................................6

SECTION 8.  ADJUSTMENT OF SHARES...............................................6

   (a)  General................................................................6
   (b)  Mergers and Consolidations.............................................7
   (c)  Reservation of Rights..................................................7

SECTION 9.  SECURITIES LAWS REQUIREMENTS.......................................7


SECTION 10. NO RETENTION RIGHTS................................................7


SECTION 11. DURATION AND AMENDMENTS............................................8

   (a)  Term of the Plan.......................................................8
   (b)  Right to Amend or Terminate the Plan...................................8
   (c)  Effect of Amendment or Termination.....................................8

SECTION 12. DEFINITIONS........................................................8

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                      TRADINGDYNAMICS, INC. 1999 STOCK PLAN



SECTION 1.  ESTABLISHMENT AND PURPOSE.

         The purpose of the Plan is to offer selected individuals an opportunity
to acquire a proprietary interest in the success of the Company, or to increase
such interest, by purchasing Shares of the Company's Stock. The Plan provides
both for the direct award or sale of Shares and for the grant of Options to
purchase Shares. Options granted under the Plan may include Nonstatutory Options
as well as ISOs intended to qualify under Section 422 of the Code.

         Capitalized terms are defined in Section 12.

SECTION 2.  ADMINISTRATION.

         (a)      Committees of the Board of Directors. The Plan may be
administered by one or more Committees. Each Committee shall consist of two or
more members of the Board of Directors who have been appointed by the Board of
Directors. Each Committee shall have such authority and be responsible for such
functions as the Board of Directors has assigned to it. If no Committee has been
appointed, the entire Board of Directors shall administer the Plan. Any
reference to the Board of Directors in the Plan shall be construed as a
reference to the Committee (if any) to whom the Board of Directors has assigned
a particular function.

         (b)      Authority of the Board of Directors. Subject to the provisions
of the Plan, the Board of Directors shall have full authority and discretion to
take any actions it deems necessary or advisable for the administration of the
Plan. All decisions, interpretations and other actions of the Board of Directors
shall be final and binding on all Purchasers, all Optionees and all persons
deriving their rights from a Purchaser or Optionee.

SECTION 3.  ELIGIBILITY.

         (a)      General Rule. Only Employees, Outside Directors and
Consultants shall be eligible for the grant of Options or the direct award or
sale of Shares. Only Employees shall be eligible for the grant of ISOs.

         (b)      Ten-Percent Shareholders. An individual who owns more than 10%
of the total combined voting power of all classes of outstanding stock of the
Company, its Parent or any of its Subsidiaries shall not be eligible for
designation as an Optionee holding an ISO unless (i) the Exercise Price is at
least 110% of the Fair Market Value of a Share on the date of grant, and (ii) in
the case of an ISO, such ISO by its terms is not exercisable after the
expiration of five years from the date of grant. For purposes of this Subsection
(b), in determining stock ownership, the attribution rules of Section 424(d) of
the Code shall be applied.

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SECTION 4.  STOCK SUBJECT TO PLAN.

         (a)      Basic Limitation. The aggregate number of Shares that may be
issued under the Plan (upon exercise of Options or other rights to acquire
Shares) shall not exceed 2,500,000 Shares, subject to adjustment pursuant to
Section 8. The number of Shares that are subject to Options or other rights
outstanding at any time under the Plan shall not exceed the number of Shares
that then remain available for issuance under the Plan. The Company, during the
term of the Plan, shall at all times reserve and keep available sufficient
Shares to satisfy the requirements of the Plan.

         (b)      Additional Shares. In the event that any outstanding Option or
other right for any reason expires or is canceled or otherwise terminated, the
Shares allocable to the unexercised portion of such Option or other right shall
again be available for the purposes of the Plan. In the event that Shares issued
under the Plan are reacquired by the Company pursuant to any forfeiture
provision, right of repurchase or right of first refusal, such Shares shall
again be available for the purposes of the Plan, except that the aggregate
number of Shares which may be issued upon the exercise of ISOs shall in no event
exceed 2,500,000 Shares (subject to adjustment pursuant to Section 8).

SECTION 5.  TERMS AND CONDITIONS OF AWARDS OR SALES.

         (a)      Stock Purchase Agreement. Each award or sale of Shares under
the Plan (other than upon exercise of an Option) shall be evidenced by a Stock
Purchase Agreement between the Purchaser and the Company. Such award or sale
shall be subject to all applicable terms and conditions of the Plan and may be
subject to any other terms and conditions which are not inconsistent with the
Plan and which the Board of Directors deems appropriate for inclusion in a Stock
Purchase Agreement. The provisions of the various Stock Purchase Agreements
entered into under the Plan need not be identical.

         (b)      Duration of Offers and Nontransferability of Rights. Any right
to acquire Shares under the Plan (other than an Option) shall automatically
expire if not exercised by the Purchaser within 30 days after the grant of such
right was communicated to the Purchaser by the Company. Such right shall not be
transferable and shall be exercisable only by the Purchaser to whom such right
was granted.

         (c)      Purchase Price. The Purchase Price of Shares to be offered
under the Plan shall not be less than the par value of such Shares. Subject to
the preceding sentence, the Purchase Price shall be determined by the Board of
Directors at its sole discretion. The Purchase Price shall be payable in a form
described in Section 7.

         (d)      Withholding Taxes. As a condition to the purchase of Shares,
the Purchaser shall make such arrangements as the Board of Directors may require
for the satisfaction of any federal, state, local or foreign withholding tax
obligations that may arise in connection with such purchase.

         (e)      Restrictions on Transfer of Shares and Minimum Vesting. Any
Shares awarded or sold under the Plan shall be subject to such special
forfeiture conditions, rights of

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repurchase, rights of first refusal and other transfer restrictions as the Board
of Directors may determine. Such restrictions shall be set forth in the
applicable Stock Purchase Agreement and shall apply in addition to any
restrictions that may apply to holders of Shares generally.

         (f)      Accelerated Vesting. Unless the applicable Stock Purchase
Agreement provides otherwise, any right to repurchase a Purchaser's Shares at
the original Purchase Price (if any) upon termination of the Purchaser's Service
shall lapse and all of such Shares shall become vested if (i) the Company is
subject to a Change in Control before the Purchaser's Service terminates and
(ii) the repurchase right is not assigned to the entity that employs the
Purchaser immediately after the Change in Control or to its parent or
subsidiary.

SECTION 6.  TERMS AND CONDITIONS OF OPTIONS.

         (a)      Stock Option Agreement. Each grant of an Option under the Plan
shall be evidenced by a Stock Option Agreement between the Optionee and the
Company. Such Option shall be subject to all applicable terms and conditions of
the Plan and may be subject to any other terms and conditions which are not
inconsistent with the Plan and which the Board of Directors deems appropriate
for inclusion in a Stock Option Agreement. The provisions of the various Stock
Option Agreements entered into under the Plan need not be identical.

         (b)      Number of Shares. Each Stock Option Agreement shall specify
the number of Shares that are subject to the Option and shall provide for the
adjustment of such number in accordance with Section 8. The Stock Option
Agreement shall also specify whether the Option is an ISO or a Nonstatutory
Option.

         (c)      Exercise Price. Each Stock Option Agreement shall specify the
Exercise Price. The Exercise Price of an ISO shall not be less than 100% of the
Fair Market Value of a Share on the date of grant, and a higher percentage may
be required by Section 3(b). The Exercise Price of a Nonstatutory Option shall
not be less than the par value of a Share on the date of grant. Subject to the
preceding two sentences, the Exercise Price under any Option shall be determined
by the Board of Directors at its sole discretion. The Exercise Price shall be
payable in a form described in Section 7.

         (d)      Withholding Taxes. As a condition to the exercise of an
Option, the Optionee shall make such arrangements as the Board of Directors may
require for the satisfaction of any federal, state, local or foreign withholding
tax obligations that may arise in connection with such exercise. The Optionee
shall also make such arrangements as the Board of Directors may require for the
satisfaction of any federal, state, local or foreign withholding tax obligations
that may arise in connection with the disposition of Shares acquired by
exercising an Option.

         (e)      Exercisability. Each Stock Option Agreement shall specify the
date when all or any installment of the Option is to become exercisable. The
exercisability provisions of any Stock Option Agreement shall be determined by
the Board of Directors at its sole discretion.

         (f)      Accelerated Exercisability. Unless the applicable Stock Option
Agreement provides otherwise, all of an Optionee's Options shall become
exercisable in full if (i) the Company is subject to a Change in Control before
the Optionee's Service terminates, (ii) such

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Options do not remain outstanding, (iii) such Options are not assumed by the
surviving corporation or its parent and (iv) the surviving corporation or its
parent does not substitute options with substantially the same terms for such
Options.

         (g)      Basic Term. The Stock Option Agreement shall specify the term
of the Option. The term shall not exceed 10 years from the date of grant, and a
shorter term may be required by Section 3(b). Subject to the preceding sentence,
the Board of Directors at its sole discretion shall determine when an Option is
to expire.

         (h)      Nontransferability. No Option shall be transferable by the
Optionee other than by beneficiary designation, will or the laws of descent and
distribution. An Option may be exercised during the lifetime of the Optionee
only by the Optionee or by the Optionee's guardian or legal representative. No
Option or interest therein may be transferred, assigned, pledged or hypothecated
by the Optionee during the Optionee's lifetime, whether by operation of law or
otherwise, or be made subject to execution, attachment or similar process.

         (i)      Termination of Service (Except by Death). If an Optionee's
Service terminates for any reason other than the Optionee's death, then the
Optionee's Options shall expire on the earliest of the following occasions:

                  (i)      The expiration date determined pursuant to Subsection
         (g) above;

                  (ii)     The date three months after the termination of the
         Optionee's Service for any reason other than Disability, or such later
         date as the Board of Directors may determine; or

                  (iii)    The date six months after the termination of the
         Optionee's Service by reason of Disability, or such later date as the
         Board of Directors may determine.

The Optionee may exercise all or part of the Optionee's Options at any time
before the expiration of such Options under the preceding sentence, but only to
the extent that such Options had become exercisable before the Optionee's
Service terminated (or became exercisable as a result of the termination) and
the underlying Shares had vested before the Optionee's Service terminated (or
vested as a result of the termination). The balance of such Options shall lapse
when the Optionee's Service terminates. In the event that the Optionee dies
after the termination of the Optionee's Service but before the expiration of the
Optionee's Options, all or part of such Options may be exercised (prior to
expiration) by the executors or administrators of the Optionee's estate or by
any person who has acquired such Options directly from the Optionee by
beneficiary designation, bequest or inheritance, but only to the extent that
such Options had become exercisable before the Optionee's Service terminated (or
became exercisable as a result of the termination) and the underlying Shares had
vested before the Optionee's Service terminated (or vested as a result of the
termination).

         (j)      Leaves of Absence. For purposes of Subsection (i) above,
Service shall be deemed to continue while the Optionee is on a bona fide leave
of absence, if such leave was approved by the Company in writing and if
continued crediting of Service for this purpose is

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expressly required by the terms of such leave or by applicable law (as
determined by the Company).

         (k)      Death of Optionee. If an Optionee dies while the Optionee is
in Service, then the Optionee's Options shall expire on the earlier of the
following dates:

                  (i)      The expiration date determined pursuant to Subsection
         (g) above; or

                  (ii)     The date 12 months after the Optionee's death.

All or part of the Optionee's Options may be exercised at any time before the
expiration of such Options under the preceding sentence by the executors or
administrators of the Optionee's estate or by any person who has acquired such
Options directly from the Optionee by beneficiary designation, bequest or
inheritance, but only to the extent that such Options had become exercisable
before the Optionee's death or became exercisable as a result of the death. The
balance of such Options shall lapse when the Optionee dies.

         (l)      No Rights as a Shareholder. An Optionee, or a transferee of an
Optionee, shall have no rights as a shareholder with respect to any Shares
covered by the Optionee's Option until such person becomes entitled to receive
such Shares by filing a notice of exercise and paying the Exercise Price
pursuant to the terms of such Option.

         (m)      Modification, Extension and Assumption of Options. Within the
limitations of the Plan, the Board of Directors may modify, extend or assume
outstanding Options or may accept the cancellation of outstanding Options
(whether granted by the Company or another issuer) in return for the grant of
new Options for the same or a different number of Shares and at the same or a
different Exercise Price. The foregoing notwithstanding, no modification of an
Option shall, without the consent of the Optionee, impair the Optionee's rights
or increase the Optionee's obligations under such Option.

         (n)      Restrictions on Transfer of Shares and Minimum Vesting. Any
Shares issued upon exercise of an Option shall be subject to such special
forfeiture conditions, rights of repurchase, rights of first refusal and other
transfer restrictions as the Board of Directors may determine. Such restrictions
shall be set forth in the applicable Stock Option Agreement and shall apply in
addition to any restrictions that may apply to holders of Shares generally.

         (o)      Accelerated Vesting. Unless the applicable Stock Option
Agreement provides otherwise, any right to repurchase an Optionee's Shares at
the original Exercise Price upon termination of the Optionee's Service shall
lapse and all of such Shares shall become vested if (i) the Company is subject
to a Change in Control before the Optionee's Service terminates and (ii) the
repurchase right is not assigned to the entity that employs the Optionee
immediately after the Change in Control or to its parent or subsidiary.

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SECTION 7.  PAYMENT FOR SHARES.

         (a)      General Rule. The entire Purchase Price or Exercise Price of
Shares issued under the Plan shall be payable in cash or cash equivalents at the
time when such Shares are purchased, except as otherwise provided in this
Section 7.

         (b)      Surrender of Stock. To the extent that a Stock Option
Agreement so provides, all or any part of the Exercise Price may be paid by
surrendering, or attesting to the ownership of, Shares that are already owned by
the Optionee. Such Shares shall be surrendered to the Company in good form for
transfer and shall be valued at their Fair Market Value on the date when the
Option is exercised. The Optionee shall not surrender, or attest to the
ownership of, Shares in payment of the Exercise Price if such action would cause
the Company to recognize compensation expense (or additional compensation
expense) with respect to the Option for financial reporting purposes.

         (c)      Services Rendered. At the discretion of the Board of
Directors, Shares may be awarded under the Plan in consideration of services
rendered to the Company, a Parent or a Subsidiary prior to the award.

         (d)      Promissory Note. To the extent that a Stock Option Agreement
or Stock Purchase Agreement so provides, all or a portion of the Exercise Price
or Purchase Price (as the case may be) of Shares issued under the Plan may be
paid with a full-recourse promissory note. The Shares shall be pledged as
security for payment of the principal amount of the promissory note and interest
thereon. The interest rate payable under the terms of the promissory note shall
not be less than the minimum rate (if any) required to avoid the imputation of
additional interest under the Code. Subject to the foregoing, the Board of
Directors (at its sole discretion) shall specify the term, interest rate,
amortization requirements (if any) and other provisions of such note.

         (e)      Exercise/Sale. To the extent that a Stock Option Agreement so
provides, and if Stock is publicly traded, payment may be made all or in part by
the delivery (on a form prescribed by the Company) of an irrevocable direction
to a securities broker approved by the Company to sell Shares and to deliver all
or part of the sales proceeds to the Company in payment of all or part of the
Exercise Price and any withholding taxes.

         (f)      Exercise/Pledge. To the extent that a Stock Option Agreement
so provides, and if Stock is publicly traded, payment may be made all or in part
by the delivery (on a form prescribed by the Company) of an irrevocable
direction to pledge Shares to a securities broker or lender approved by the
Company, as security for a loan, and to deliver all or part of the loan proceeds
to the Company in payment of all or part of the Exercise Price and any
withholding taxes.

SECTION 8.  ADJUSTMENT OF SHARES.

         (a)      General. In the event of a subdivision of the outstanding
Stock, a declaration of a dividend payable in Shares, a declaration of an
extraordinary dividend payable in a form other than Shares in an amount that has
a material effect on the Fair Market Value of the Stock, a

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combination or consolidation of the outstanding Stock into a lesser number of
Shares, a recapitalization, a spin-off, a reclassification or a similar
occurrence, the Board of Directors shall make appropriate adjustments in one or
more of (i) the number of Shares available for future grants under Section 4,
(ii) the number of Shares covered by each outstanding Option or (iii) the
Exercise Price under each outstanding Option.

         (b)      Mergers and Consolidations. In the event that the Company is a
party to a merger or consolidation, outstanding Options shall be subject to the
agreement of merger or consolidation. Such agreement, without the Optionees'
consent, may provide for:

                  (i)      The continuation of such outstanding Options by the
         Company (if the Company is the surviving corporation);

                  (ii)     The assumption of the Plan and such outstanding
         Options by the surviving corporation or its parent;

                  (iii)    The substitution by the surviving corporation or its
         parent of options with substantially the same terms for such
         outstanding Options; or

                  (iv)     The cancellation of such outstanding Options without
         payment of any consideration.

         (c)      Reservation of Rights. Except as provided in this Section 8,
an Optionee or Purchaser shall have no rights by reason of (i) any subdivision
or consolidation of shares of stock of any class, (ii) the payment of any
dividend or (iii) any other increase or decrease in the number of shares of
stock of any class. Any issuance by the Company of shares of stock of any class,
or securities convertible into shares of stock of any class, shall not affect,
and no adjustment by reason thereof shall be made with respect to, the number or
Exercise Price of Shares subject to an Option. The grant of an Option pursuant
to the Plan shall not affect in any way the right or power of the Company to
make adjustments, reclassifications, reorganizations or changes of its capital
or business structure, to merge or consolidate or to dissolve, liquidate, sell
or transfer all or any part of its business or assets.

SECTION 9.  SECURITIES LAW REQUIREMENTS.

         Shares shall not be issued under the Plan unless the issuance and
delivery of such Shares comply with (or are exempt from) all applicable
requirements of law, including (without limitation) the Securities Act of 1933,
as amended, the rules and regulations promulgated thereunder, state securities
laws and regulations, and the regulations of any stock exchange or other
securities market on which the Company's securities may then be traded.

SECTION 10. NO RETENTION RIGHTS.

         Nothing in the Plan or in any right or Option granted under the Plan
shall confer upon the Purchaser or Optionee any right to continue in Service for
any period of specific duration or interfere with or otherwise restrict in any
way the rights of the Company (or any Parent or Subsidiary employing or
retaining the Purchaser or Optionee) or of the Purchaser or Optionee,

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which rights are hereby expressly reserved by each, to terminate his or her
Service at any time and for any reason, with or without cause.

SECTION 11. DURATION AND AMENDMENTS.

         (a)      Term of the Plan. The Plan, as set forth herein, shall become
effective on the date of its adoption by the Board of Directors, subject to the
approval of the Company's shareholders. In the event that the shareholders fail
to approve the Plan within 12 months after its adoption by the Board of
Directors, any grants of Options or sales or awards of Shares that have already
occurred shall be rescinded, and no additional grants, sales or awards shall be
made thereafter under the Plan. The Plan shall terminate automatically 10 years
after its adoption by the Board of Directors and may be terminated on any
earlier date pursuant to Subsection (b) below.

         (b)      Right to Amend or Terminate the Plan. The Board of Directors
may amend, suspend or terminate the Plan at any time and for any reason;
provided, however, that any amendment of the Plan which increases the number of
Shares available for issuance under the Plan (except as provided in Section 8),
or which materially changes the class of persons who are eligible for the grant
of ISOs, shall be subject to the approval of the Company's shareholders.
Shareholder approval shall not be required for any other amendment of the Plan.

         (c)      Effect of Amendment or Termination. No Shares shall be issued
or sold under the Plan after the termination thereof, except upon exercise of an
Option granted prior to such termination. The termination of the Plan, or any
amendment thereof, shall not affect any Share previously issued or any Option
previously granted under the Plan.

SECTION 12. DEFINITIONS.

         (a)      "Board of Directors" shall mean the Board of Directors of the
Company, as constituted from time to time.

         (b)      "Change in Control" shall mean:

                  (i)      The consummation of a merger or consolidation of the
         Company with or into another entity or any other corporate
         reorganization, if persons who were not shareholders of the Company
         immediately prior to such merger, consolidation or other reorganization
         own immediately after such merger, consolidation or other
         reorganization 50% or more of the voting power of the outstanding
         securities of each of (A) the continuing or surviving entity and (B)
         any direct or indirect parent corporation of such continuing or
         surviving entity; or

                  (ii)     The sale, transfer or other disposition of all or
         substantially all of the Company's assets.

A transaction shall not constitute a Change in Control if its sole purpose is to
change the state of the Company's incorporation or to create a holding company
that will be owned in substantially

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the same proportions by the persons who held the Company's securities
immediately before such transaction.

         (c)      "Code" shall mean the Internal Revenue Code of 1986, as
amended.

         (d)      "Committee" shall mean a committee of the Board of Directors,
as described in Section 2(a).

         (e)      "Company" shall mean TradingDynamics, Inc., a California
corporation.

         (f)      "Consultant" shall mean a person who performs bona fide
services for the Company, a Parent or a Subsidiary as a consultant or advisor,
excluding Employees and Outside Directors.

         (g)      "Disability" shall mean that the Optionee is unable to engage
in any substantial gainful activity by reason of any medically determinable
physical or mental impairment.

         (h)      "Employee" shall mean any individual who is a common-law
employee of the Company, a Parent or a Subsidiary.

         (i)      "Exercise Price" shall mean the amount for which one Share may
be purchased upon exercise of an Option, as specified by the Board of Directors
in the applicable Stock Option Agreement.

         (j)      "Fair Market Value" shall mean the fair market value of a
Share, as determined by the Board of Directors in good faith. Such determination
shall be conclusive and binding on all persons.

         (k)      "ISO" shall mean an employee incentive stock option described
in Section 422(b) of the Code.

         (l)      "Nonstatutory Option" shall mean a stock option not described
in Sections 422(b) or 423(b) of the Code.

         (m)      "Option" shall mean an ISO or Nonstatutory Option granted
under the Plan and entitling the holder to purchase Shares.

         (n)      "Optionee" shall mean an individual who holds an Option.

         (o)      "Outside Director" shall mean a member of the Board of
Directors who is not an Employee.

         (p)      "Parent" shall mean any corporation (other than the Company)
in an unbroken chain of corporations ending with the Company, if each of the
corporations other than the Company owns stock possessing 50% or more of the
total combined voting power of all classes of stock in one of the other
corporations in such chain. A corporation that attains the status of a Parent on
a date after the adoption of the Plan shall be considered a Parent commencing as
of such date.

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         (q)      "Plan" shall mean this TradingDynamics, Inc. 1999 Stock Plan.

         (r)      "Purchase Price" shall mean the consideration for which one
Share may be acquired under the Plan (other than upon exercise of an Option), as
specified by the Board of Directors.

         (s)      "Purchaser" shall mean an individual to whom the Board of
Directors has offered the right to acquire Shares under the Plan (other than
upon exercise of an Option).

         (t)      "Service" shall mean service as an Employee, Outside Director
or Consultant.

         (u)      "Share" shall mean one share of Stock, as adjusted in
accordance with Section 8 (if applicable).

         (v)      "Stock" shall mean the Common Stock of the Company.

         (w)      "Stock Option Agreement" shall mean the agreement between the
Company and an Optionee which contains the terms, conditions and restrictions
pertaining to the Optionee's Option.

         (x)      "Stock Purchase Agreement" shall mean the agreement between
the Company and a Purchaser who acquires Shares under the Plan which contains
the terms, conditions and restrictions pertaining to the acquisition of such
Shares.

         (y)      "Subsidiary" means any corporation (other than the Company) in
an unbroken chain of corporations beginning with the Company, if each of the
corporations other than the last corporation in the unbroken chain owns stock
possessing 50% or more of the total combined voting power of all classes of
stock in one of the other corporations in such chain. A corporation that attains
the status of a Subsidiary on a date after the adoption of the Plan shall be
considered a Subsidiary commencing as of such date.

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                               FIRST AMENDMENT TO
                      TRADINGDYNAMICS, INC. 1999 STOCK PLAN
                           Amended as of April 4, 2001

I.       Purpose of the Amendment.
         ------------------------

                  On January 20, 2000, Ariba, Inc. consummated a merger among
Ariba, Inc., Blue Merger Corporation, a wholly owned subsidiary of Ariba, Inc.,
and TradingDynamics, Inc., a California corporation (the "Merger"), pursuant to
which the TradingDynamics, Inc. 1999 Stock Plan (the "Plan") was assumed by
Ariba, Inc., including all outstanding options under the Plan. As a result of
the Merger and the assumption of the Plan, Ariba, Inc. wishes to amend the Plan
in several minor respects in order to permit Ariba, Inc. to grant options under
the assumed Plan.

II.      Amendment to Plan.
         -----------------

                  As of April 4, 2001, the Plan is hereby amended as follows:

                  (a)      The first sentence of Subsection 4(a) of the Plan is
hereby amended by substituting the number "1,097,162" for the number
"2,500,000." The first sentence of Subsection 4(a) of the Plan shall henceforth
read as follows:

                           Basic Limitation. The aggregate number of Shares that
                           may be issued under the Plan (upon exercise of
                           Options or other rights to acquire Shares) shall not
                           exceed 1,097,162 Shares subject to adjustment
                           pursuant to Section 8.

                  (b)      The last sentence of Subsection 4(b) is hereby
amended by substituting the number "1,097,162" for the number "2,500,000." The
last sentence of Subsection 4(b) shall henceforth read as follows:

                           In the event that Shares issued under the Plan are
                           reacquired by the Company pursuant to any forfeiture
                           provision, right of repurchase or right of first
                           refusal, such Shares shall again be available for the
                           purposes of the Plan, except that the aggregate
                           number of Shares which may be issued upon the
                           exercise of ISOs shall in no event exceed 1,097,162
                           Shares (subject to adjustment pursuant to Section 8).

                  (c)      Subsection 12(d) of the Plan is hereby amended by
providing that the members of the Committee must meet the requirements for
administrators and outside directors acting under plans intended to qualify for
exemption under Rule 16b-3 of the Securities Exchange Act of 1934 and Section
162(m)(4)(C) of the Internal Revenue Code. Subsection 12(d) of the Plan shall
henceforth read as follows:

                           "Committee" shall mean a committee of two (2) or more
                           members of the Board of Directors appointed by the
                           Board of Directors to exercise one or more
                           administrative functions under the Plan. In addition,
                           the composition of the Committee shall satisfy:

<PAGE>

                           (i)      Such requirements as the Securities and
                           Exchange Commission may establish for administrators
                           acting under plans intended to qualify for exemption
                           under Rule 16b-3 (or its successor) under the
                           Securities Exchange Act of 1934 as amended; and

                           (ii)     Such requirements as the Internal Revenue
                           Service may establish for outside directors acting
                           under plans intending to qualify for exemption under
                           Section 162(m)(4)(C) of the Code.

                  (d)      Subsection 12(e) of the Plan is hereby amended by
substituting the word "Ariba" for the word "TradingDynamics," and by
substituting the word "Delaware" for the word "California" Subsection 12(e) of
the Plan shall henceforth read as follows:

                           "Company" shall mean Ariba, Inc., a Delaware
corporation.

III.     Effective Date.
         --------------

                  This First Amendment shall be effective upon its approval by
the Compensation Committee of the Board of Directors of Ariba, Inc.

IV.      Effect on the Plan.
         ------------------

                  Except as expressly amended hereby, the Plan shall remain
unchanged and in full force and effect and is hereby ratified and confirmed.

                                        2

<PAGE>

                               FIRST AMENDMENT TO
                            SUPPLIERMARKET.COM, INC.
                             1999 STOCK OPTION PLAN
                           Amended as of April 4, 2001



         I.       Purpose of the Amendment.
                  ------------------------

         On or about August 28, 2000, the Company consummated a merger among
Ariba, Inc. and Eli Merger Corporation, a wholly-owned subsidiary of Ariba,
Inc., and suppliermarket.com, Inc., a Delaware corporation (the "Merger"),
pursuant to which the suppliermarket.com, Inc. 1999 Stock Option Plan (the
"Plan") was assumed by Ariba, Inc., including all outstanding options under the
Plan. As a result of the Merger and the assumption of the Plan, Ariba, Inc.
wishes to amend the Plan to include Ariba, Inc. within the definition of
"Company" under the Plan in order to permit Ariba, Inc. to grant options under
the assumed Plan, and to permit alternate payment methods for the exercise of
options under the assumed Plan.

         II.      Amendment to Plan.
                  -----------------

         As of April 4, 2001, the Plan is hereby amended as follows:

                  (a)      The first sentence in the first paragraph of the Plan
is hereby amended by (i) substituting the words "Ariba, Inc." for the words
"suppliermarket.com, Inc.," (ii) changing the number "2,625,962" for the number
"2,472,690," and (iii) changing the par value to $.02. The first sentence of the
first paragraph of the Plan shall henceforth read as follows:

                  This Plan (this "Plan") of Ariba, Inc. (the "Company")
                  provides that options for up to 2,472,690 shares (the
                  "Shares") of the Company's Common Stock, $.02 par value per
                  share (the "Stock"), may be granted to employees of the
                  Company and its subsidiaries, as defined below, and to others
                  who are in a position to make significant contributions to the
                  success of the Company and its subsidiaries.

                  (b)      Section 10(a) is hereby amended by deleting the word
"or" before the Subsection "(iii)" and by adding the phrase "or (iv) by any
method provided for by the Board or Committee in its discretion that is
permitted by law." Section 10(a) shall henceforth read as follows:

                  Exercise Price. The exercise price for Shares purchased under
                  an option shall be paid as follows: (i) in cash or by
                  certified check, bank draft or money order payable to the
                  order of the Company; (ii) if permitted by the terms of the
                  instrument granting the option, by the delivery of shares of
                  Stock having a fair market value (as determined by the Board
                  in good faith in its reasonable discretion) on the date of
                  exercise equal to the exercise price; (iii) by a combination
                  of cash and

<PAGE>

                  Stock; provided, however, that payment of the exercise price
                  by delivery of shares of Common Stock of the Company owned by
                  such optionholder may be made only if such payment does not
                  result in a charge to earnings for financial accounting
                  purposes as determined by the Board, unless the Board
                  otherwise permits such payment by delivery of shares of Common
                  Stock; or (iv) by any method provided for by the Board or
                  Committee in its discretion that is permitted by law.

         III.     Effective Date.
                  --------------

         This First Amendment shall be effective upon its approval by the
Compensation Committee of the Board of Directors of Ariba, Inc.

         IV.      Effect on the Plan.
                  ------------------

         Except as expressly amended hereby, the Plan shall remain unchanged and
in full force and effect and is hereby ratified and confirmed.

                                        2