<PAGE>

                                                                    EXHIBIT 10.1

                               FIRST AMENDMENT TO
                           THIRD AMENDED AND RESTATED
                           REVOLVING CREDIT AGREEMENT

                                      AMONG

                         AMERITRADE HOLDING CORPORATION
                                       AND
                     FIRST NATIONAL BANK OF OMAHA, AS AGENT
                                       AND
                         REVOLVING LENDERS PARTY HERETO

                          DATED AS OF DECEMBER 13, 2004

<PAGE>

                  FIRST AMENDMENT TO THIRD AMENDED AND RESTATED
                           REVOLVING CREDIT AGREEMENT

      THIS FIRST AMENDMENT to THIRD AMENDED AND RESTATED REVOLVING CREDIT
AGREEMENT (this "First Amendment") entered into as of this 13th day of December,
2004, is intended to amend the terms of the Third Amended and Restated Revolving
Credit Agreement (the "Agreement") dated as of the 15th day of December, 2003,
among AMERITRADE HOLDING CORPORATION a Delaware corporation having its principal
place of business at 4211 South 102nd Street, Omaha, Nebraska 68127 (the
"Borrower"), FIRST NATIONAL BANK OF OMAHA, a national banking association having
its principal place of business at 1620 Dodge Street, Omaha, Nebraska 68197-1050
("Agent" or "FNB-O"), LASALLE BANK NATIONAL ASSOCIATION, a national banking
association having its principal place of business at 801 Grand Street, Suite
3150, Des Moines, Iowa 50309 , M&I MARSHALL & ILSLEY BANK, a Wisconsin banking
association having its principal place of business at 770 North Water Street,
Milwaukee, Wisconsin 53201-2035, WELLS FARGO BANK, NATIONAL ASSOCIATION, a
national banking association having its principal place of business at 1919
Douglas Street, Omaha, Nebraska 68102, and such other lenders as may become
Revolving Lenders under the Agreement. All terms and conditions of the Agreement
shall remain in full force and effect except as expressly amended herein. All
capitalized terms used but not otherwise defined herein shall have the
respective meanings prescribed in the Agreement.

      WHEREAS, the Borrower has requested and the Revolving Lenders have agreed
to make certain amendments to the Agreement, including increasing the Base
Revolving Credit Facility to $105,000,000 and extending the Termination Date to
December 12, 2005; and

      WHEREAS, the Borrower and the Revolving Lenders are willing to make such
amendments on the terms set forth below.

      NOW, THEREFORE, the parties hereby agree that as of the date hereof (the
"Effective Date"):

1.    The following definition under Article I of the Agreement is hereby
      amended and restated in its entirety to read as follows:

      Agreement:        This Third Amended and Restated Revolving Credit
                        Agreement, dated as of December 15, 2003, among the
                        Borrower and the Revolving Lenders, as amended by the
                        First Amendment to Third Amended and Restated Revolving
                        Credit Agreement, dated as of December 13, 2004, as
                        further amended or restated from time to time.

2.    The following definition under Article I of the Agreement is hereby
      amended and restated in its entirety to read as follows:

      Applicable
      Margin:           For purposes of determining the Revolving Credit Rate,
                        the margin, calculated on a quarterly basis, is as
                        follows:

                        (a) If the Quarterly Compliance Certificate for the
                            immediately preceding fiscal

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<PAGE>

                            quarter shows that the Leverage Ratio is less than
                            or equal to 0.25, the margin for the current quarter
                            shall be plus 1.75%; and

                        (b) If the Quarterly Compliance Certificate for the
                            immediately preceding fiscal quarter shows that the
                            Leverage Ratio is greater than 0.25 and less than or
                            equal to 0.50, the margin for the current quarter
                            shall be plus 2.00%.

                        In the event that any Quarterly Compliance Certificate
                        is not delivered on or before the due date thereof, the
                        Applicable Margin shall be the margin set forth in (b)
                        above until such certificate is delivered.

3.    The following definition is hereby added to Article I of the Agreement as
      follows:

      Cash Capital
      Expenditure:      The amount of any cash paid by the Borrower for any
                        capital expenditure pursuant to Section 4.15, whether
                        such payment is a cash down payment, a cash payment on
                        financed capital expenditures (other than regularly
                        scheduled monthly payments on financed capital
                        expenditures) or a cash payment in full.

4.    The following definition is hereby added to Article I of the Agreement as
      follows:

      EBITDA:           At any time, for the prior four fiscal quarters, the
                        Borrower's net income on a consolidated basis, plus (a)
                        taxes paid or accrued during such period, (b) interest
                        expenses paid or accrued during such period (other than
                        interest expenses paid to clients or accrued on cash
                        balances), and (c) amortization and depreciation
                        deducted in determining such net income for such period.

5.    The following definition under Article I of the Agreement is hereby
      amended and restated in its entirety to read as follows:

      Investments:      (i) Any direct or indirect purchase or other acquisition
                        by the Borrower or any of its Subsidiaries of, or of a
                        beneficial interest in, any securities of any other
                        Person (including any Subsidiary of the Borrower), or
                        (ii) any direct or indirect loan, advance (other than
                        advances to employees for moving, entertainment and
                        travel expenses, drawing accounts and similar
                        expenditures in the ordinary course of business) or
                        capital contribution by the Borrower or any of its
                        Subsidiaries to any other Person, but excluding
                        Acquisitions. For the avoidance of doubt, transactions
                        in funds, securities or other property held or carried
                        by the Borrower or any of its Subsidiaries for the
                        benefit or account of any customer or other Person shall
                        not be considered Investments.

6.    The following definition under Article I of the Agreement is hereby
      amended and restated in its entirety to read as follows:

      Letter(s) of
      Credit:           Letter(s) of Credit issued under the Letter of Credit
                        Facility, the Letter of Credit

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                        Amount of which shall not exceed $25,000,000.00 at any
                        time.

7.    The following definition under Article I of the Agreement is hereby
      amended and restated in its entirety to read as follows:

      Leverage
      Ratio:            Permitted Indebtedness divided by EBITDA.

8.    The definition of "Minimum Liquid Assets" is hereby deleted in its
      entirety from the Agreement.

9.    The following definition under Article I of the Agreement is hereby
      amended and restated in its entirety to read as follows:

      Money Market
      Funds:            At any time, money market funds whose rating from
                        Standard and Poor's Rating Services Group ("S&P") is
                        AAAm or AAm or the equivalent thereof or whose Moody's
                        Investor Services ("Moody's") rating is Aaa or Aa or the
                        equivalent thereof.

10.   The following definition is hereby added to Article I of the Agreement as
      follows:

      Net Worth:        The Borrower's consolidated net worth as determined in
                        accordance with GAAP.

11.   The following definition under Article I of the Agreement is hereby
      amended and restated in its entirety to read as follows:

      Permitted
      Investments:      Any one or more of the following:

                              (a) certificates of deposit fully covered by
                        Federal Deposit Insurance and maintained at a bank
                        having capital and surplus of not less than $50,000,000;

                              (b) short-term obligations of, or obligations
                        fully guaranteed by, the United States of America or any
                        agencies thereof;

                              (c) commercial paper rated at least A-1 by
                        Standard and Poor's Ratings Service or P-1 by Moody's
                        Investors Service, Inc.;

                              (d) demand deposit accounts maintained in the
                        ordinary course of the business at a bank having capital
                        and surplus of not less than $50,000,000;

                              (e) Money Market Funds;

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<PAGE>

                              (f) AA Rated or equivalent (or better) variable
                        rate preferred stock or debt;

                              (g) AA Rated or equivalent (or better) municipal
                        notes and bonds; and

                              (h) overnight repurchase agreements and term
                        repurchase agreements with a maturity up to two years
                        with respect to, and which are fully secured by a
                        security interest in, direct obligations issued by or
                        fully guaranteed by the United States of America, and
                        that are entered into with any commercial bank organized
                        under the laws of the United States of America or any
                        state thereof or the District of Columbia that (a) is at
                        least "adequately capitalized" (as defined in the
                        regulations of its primary Federal banking regulator)
                        and (b) has Tier 1 capital (as defined in such
                        regulations) of not less than $100,000,000.

                  provided, however, that the percentage of the Borrower's
                  investment portfolio that can be invested in AA Rated
                  securities is limited to twenty-five percent (25%) of the
                  Borrower's total investment portfolio, valued in accordance
                  with GAAP, so long as the remainder of the Borrower's
                  investment portfolio is invested in at least AAA securities
                  (or the equivalent rating for short-term investments) or in
                  items described in clauses (a) through (e) above; provided
                  further, that the maturities for any Permitted Investments
                  shall not exceed two years; and provided further, that the
                  average maturity of the Borrower's investment portfolio at all
                  times cannot exceed two hundred seventy (270) days. For
                  purposes of this definition, "maturity" includes final
                  maturity, or the put or pre-refunding date when securities are
                  to be liquidated at a predetermined price (usually par value).

12.   The following definition is hereby added to Article I of the Agreement as
      follows:

      Quarterly
      Compliance
      Certificate:      The certificate delivered to the Revolving Lenders by
                        the Borrower pursuant to Section 4.1(e).

13.   The following definition under Article I of the Agreement is hereby
      amended and restated in its entirety to read as follows:

      Termination
      Date:             December 12, 2005, or such later date as is approved in
                        writing by the Revolving Lenders.

14.   The following definition is hereby added to Article I of the Agreement as
      follows:

      Unrestricted
      Liquidity:        The sum of (i) all Non-Broker-Dealer Cash, plus (ii)
                        Distributable Net Capital.

15.   Section 2.1 of the Agreement is hereby amended and restated in its
      entirety to read as follows:

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<PAGE>

                        2.1 Revolving Credit. Until December 12, 2005, the
                  Revolving Lenders severally agree to advance funds for general
                  corporate purposes not to exceed the amount shown on Appendix
                  I attached hereto, as amended from time to time (the "Base
                  Revolving Credit Facility"), to the Borrower on a revolving
                  credit basis.

                        Such Advances shall be made on a pro rata basis by the
                  Revolving Lenders, based on the maximum Advance limits and
                  applicable percentages for each Revolving Lender as shown on
                  Appendix I attached hereto, as amended from time to time;
                  provided, however, that each Revolving Lender's Commitment is
                  several and not joint or joint and several.

                        The Borrower shall not be entitled to any Advance
                  hereunder if, after the making of such Advance, the Principal
                  Loan Amount would exceed the then current Base Revolving
                  Credit Facility after giving effect to the requested Advance.
                  Nor shall the Borrower be entitled to any further Advances
                  hereunder after the occurrence and during the continuation of
                  any Event of Default or Potential Event of Default, or if the
                  Borrower's representations and warranties hereunder are not
                  true and correct in all material respects as of the time of
                  the requested Advance. Advances shall be made, on the terms
                  and conditions of this Agreement, upon the Borrower's request.
                  Requests shall be made by 11:00 a.m. Omaha time on the
                  Business Day prior to the requested date of the Advance.
                  Requests shall be made by presentation to FNB-O of a drawing
                  certificate in the form of Exhibit B. The Borrower's
                  obligation to make payments of principal and interest on the
                  foregoing revolving credit indebtedness shall be further
                  evidenced by the Notes. FNB-O shall promptly transmit a copy
                  of each such Advance request to the other Revolving Lenders.
                  Each Revolving Lender shall remit to FNB-O its Commitment
                  percentage times the amount of the Advance request, subject to
                  the conditions specified hereunder. Such remittance shall be
                  transferred to FNB-O on the same Business Day as to requests
                  received by such Revolving Lender before 12:00 noon of a
                  Business Day, and as to requests received thereafter, on the
                  next Business Day.

16.   The phrase "provided, however, that the commitment fee for the calendar
      quarter ending December 31st, 2003 shall accrue from December 15, 2003"
      shall be deleted from Section 2.2(a) of the Agreement.

17.   Section 2.3 of the Agreement is hereby amended and restated in its
      entirety to read as follows:

                        2.3 Interest on Revolving Credit. Interest shall accrue
                  on the Principal Loan Amount outstanding from time to time at
                  a variable rate per annum (the "Revolving Credit Rate") equal
                  to the LIBOR Rate plus the Applicable Margin. Such rate shall
                  fluctuate monthly based on changes in such rate on the first
                  day of each month. If at any time no LIBOR Rate exists,
                  interest shall accrue on the Principal Loan Amount outstanding
                  from time to time at a rate equal to the National Prime Rate
                  minus 1.00%. All interest under the Notes shall accrue based
                  on a year of 360 days, and for actual days elapsed. Interest
                  for any month shall be due no later than the tenth day of the
                  following month. Notwithstanding anything to the contrary
                  elsewhere herein, after an Event of

                                       5
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                  Default has occurred and is continuing, interest shall accrue
                  on the entire outstanding balance of principal and interest on
                  all indebtedness hereunder at a fluctuating rate per annum
                  equal to the Default Rate.

18.   Section 2.4 of the Agreement is hereby amended and restated in its
      entirety to read as follows:

                        2.4 Payments. On the next succeeding Business Day after
                  the end of any Fiscal Month the Borrower shall repay the
                  amount, if any, outstanding on the Notes that in the aggregate
                  exceeds the amount of the Base Revolving Credit Facility to be
                  in place on the next succeeding Business Day following such
                  Fiscal Month. The balance of the loan on December 12, 2005, if
                  any, shall be due on the Termination Date. All obligations of
                  the Borrower under the Notes and under the other Operative
                  Documents shall be payable in immediately available funds in
                  lawful money of the United States of America at the principal
                  office of FNB-O in Omaha, Nebraska or at such other address as
                  may be designated by FNB-O in writing. In the event that a
                  payment day is not a Business Day, the payment shall be due on
                  the next succeeding Business Day.

19.   In Section 2.7 of the Agreement, "$15,000,000" is hereby deleted from such
      Section and replaced with "$25,000,000."

20.   The phrase "including a default of the Leverage Ratio covenant under
      Section 4.19" is hereby deleted from Section 2.7 of the Agreement.

21.   The phrase "two percent (2.0%) per annum" is hereby deleted from Section
      2.9 of the Agreement and replaced with the phrase "one percent (1.0%) per
      annum."

22.   The phrase "provided, however, that the Letter of Credit Fee for the
      calendar quarter ending December 31st, 2003 shall accrue from December 15,
      2003" is hereby deleted from Section 2.9 of the Agreement.

23.   Sections 4.1(d), (e) and (f) of the Agreement are hereby amended and
      restated in their entirety and Section 4.1(g) is hereby added, to read as
      follows:

                              (d) Within thirty (30) days after the end of each
                        month, the Borrower shall cause Ameritrade Online to
                        provide to the Agent the FOCUS report of Ameritrade,
                        Inc. for such month.

                              (e) Within thirty (30) days after the end of each
                        quarter, the Borrower, at its sole expense, shall
                        furnish the Agent a certificate of the chief financial
                        officer, managing director of finance or treasurer of
                        the Borrower in the form of Exhibit E attached hereto,
                        setting forth such information (including detailed
                        calculations) sufficient to verify the conclusions of
                        such officer after due inquiry and review, that:

                                  (i) The Borrower and each Subsidiary, either
                              (y) is in compliance with the requirements set
                              forth in this Agreement or (z) is NOT in
                              compliance with the foregoing for reasons
                              specifically set forth therein; and

                                       6
<PAGE>

                                  (ii) The chief financial officer, managing
                              director of finance or treasurer of the Borrower
                              has reviewed or caused to be reviewed all of the
                              terms of the Operative Documents of the Borrower
                              and each Guarantor and that such review either (y)
                              has NOT disclosed the existence of any condition
                              or event which constitutes an Event of Default or
                              a Potential Event of Default under the Operative
                              Documents or (z) has disclosed the existence of a
                              condition or event which constitutes an Event of
                              Default or a Potential Event of Default, under the
                              aforesaid instrument or instruments and the
                              specific condition or event is specifically set
                              forth.

                              (f) Within thirty (30) days after the end of each
                        month, the Borrower, at its sole expense, shall furnish
                        the Agent a certificate of the chief financial officer,
                        managing director of finance or treasurer of the
                        Borrower in the form of Exhibit C attached hereto,
                        setting forth such information (including detailed
                        calculations) sufficient to verify the conclusions of
                        such officer after due inquiry and review, that the
                        Borrower and each Subsidiary is in compliance with the
                        liquidity requirements set forth in Section 4.6 of this
                        Agreement, such certificate to be effective until the
                        due date of the next certificate pursuant to this
                        subsection.

                              (g) The Borrower shall provide the Agent with such
                        other financial reports and statements as the Revolving
                        Lenders may reasonably request.

24.   Section 4.6(b) of the Agreement is hereby amended and restated in its
      entirety to read as follows:

                              (b) The Borrower shall not redeem stock or
                        Subordinated Debt (x) during any Fiscal Month with an
                        aggregate redemption value greater than Unrestricted
                        Liquidity as reported as of the last day of the
                        preceding Fiscal Month, minus the sum of (i) the amount
                        of cash paid as purchase price in any Acquisitions and
                        (ii) the amount of any Cash Capital Expenditures (net of
                        the actual cash of any financing of prior Cash Capital
                        Expenditures received by the Borrower), in each case
                        during the Fiscal Month in which such redemptions are
                        effected or (y) at any time at which an Event of Default
                        or Potential Event of Default has occurred and is
                        continuing or would exist after giving effect to such
                        redemption.

25.   Section 4.8(e) is hereby added to the Agreement to read as follows:

                              (e) During the term of this Agreement, the
                        Borrower and each of the Guarantors shall procure and
                        maintain, at each of their own expense, insurance
                        covering the Collateral (other than the Pledged Stock
                        and Stock Rights described in the Pledge Agreements)
                        against such risks as are customarily insured against by
                        similarly situated companies. The Borrower and each of
                        the Guarantors shall name the Agent, on behalf of the
                        Revolving Lenders, as an "additional insured" under all
                        liability insurance policies covering the Collateral and
                        shall take all such other actions and execute such other
                        documents as may be requested by the

                                       7
<PAGE>

                        Agent to obtain its status as an "additional insured."
                        Upon the request of the Agent, each of the Borrower and
                        the Guarantors shall provide the Agent evidence of such
                        insurance.

26.   Section 4.13 of the Agreement is hereby amended and restated in its
      entirety to read as follows:

                        4.13 Notice of Change in Ownership. During the term of
                  this Agreement, the Borrower shall give the Revolving Lenders
                  notice of the occurrence of a Change of Control or any change,
                  directly or indirectly, in the existing controlling interest
                  in any Guarantor, which notice shall be given as soon as the
                  Borrower obtains notice or knowledge of such change.

27.   Section 4.15 of the Agreement is hereby amended and restated in its
      entirety to read as follows:

                        4.15 Capital Expenditures. The Borrower and the
                  Subsidiaries shall not incur capital expenditures in any
                  fiscal year, determined in accordance with generally accepted
                  accounting principles, of more than $50,000,000.00 in the
                  aggregate.

28.   Section 4.18 of the Agreement is hereby amended and restated in its
      entirety to read as follows:

                        4.18 Regulatory Net Capital Requirement. Ameritrade,
                  Inc. and any other Broker-Dealer Subsidiary that is a Material
                  Subsidiary will have Regulatory Net Capital at all times in
                  compliance with law but in no event less than five percent
                  (5%) of aggregate debit items.

29.   Section 4.19 of the Agreement is hereby amended and restated in its
      entirety to read as follows:

                        4.19 Leverage Ratio. The Borrower shall at all times
                  maintain on a consolidated basis a Leverage Ratio of not more
                  than 0.5.

30.   Section 4.23 is hereby added to the Agreement as follows:

                        4.23 Net Worth. The Borrower shall maintain a minimum
                  Net Worth during the term of this Agreement of at least
                  $1,100,000,000.00.

31.   Section 6.1(d) of the Agreement is hereby amended and restated in its
      entirety to read as follows:

                              (d) A failure of the Borrower or any Subsidiary to
                        comply with any requirement or restriction applicable to
                        such entity and contained in Sections 4.2, 4.3, 4.6,
                        4.10, 4.11, 4.14, 4.15, 4.16, 4.18, 4.19, 4.20 (but
                        solely if a lien has attached to assets of the Borrower
                        or any Subsidiary as a result of such failure), 4.21 or
                        4.23 of this Agreement.

32.   Appendix I currently attached to the Agreement is hereby amended and
      restated in its entirety to read as shown on Attachment I to this First
      Amendment.

33.   The form of Notes currently attached as Exhibit A to the Agreement is
      hereby amended and

                                       8
<PAGE>

      restated in its entirety to read as shown on Attachment A to this First
      Amendment.

34.   The drawing certificate currently attached as Exhibit B to the Agreement
      is hereby amended and restated in its entirety to read as shown on
      Attachment B to this First Amendment.

35.   The liquidity certificate currently attached as Exhibit C to the Agreement
      is hereby amended and restated in its entirety to read as shown on
      Attachment C to this First Amendment.

36.   The Quarterly Compliance Certificate shown on Attachment D to this First
      Amendment is hereby added to the Agreement.

37.   In consideration of the Revolving Lenders entering into this First
      Amendment, the Borrower agrees to pay to the Agent on or before the
      Effective Date (i) an amendment fee equal to the product of two basis
      points (.0002) and the existing aggregate commitment set forth in Section
      2.1 of the Agreement, without giving effect to this First Amendment,
      ($15,000), and (ii) a commitment fee equal to the product of ten basis
      points (.0010) and the aggregate increase in the commitment set forth in
      Appendix I attached to this First Amendment ($30,000), such fees to be
      distributed amongst the Revolving Lenders based, respectively, on their
      existing and increased commitments, all as evidenced on Attachment I to
      this First Amendment.

38.   Ameritrade Online Holdings Corp. ("Ameritrade Online") and Datek Online
      Holdings Corp. ("Datek" and, together with Ameritrade Online, the
      "Guarantors") hereby reaffirm and acknowledge their respective guaranty
      obligations under that certain Amended and Restated Guaranty Agreement,
      dated as of December 15, 2003, between Ameritrade Online and the Agent,
      and that certain Second Amended and Restated Guaranty Agreement, dated as
      of December 15, 2003, between Datek and the Agent.

39.   On or prior to the Effective Date, the Borrower shall deliver to the
      Agent:

      (a)   the replacement Notes;

      (b)   a certificate of an executive officer of the Borrower, dated as of
            the Effective Date, affirming as of such Effective Date (i) that the
            representations and warranties of the Borrower set forth in the
            Operative Documents are true and correct in all material respects as
            of the Effective Date, and (ii) that no Potential Event of Default
            or Event of Default has occurred and is continuing, after giving
            effect to the Waiver, dated as of December 3, 2004 (the "Waiver"),
            given by the Revolving Lenders;

      (c)   a certificate of the secretary or assistant secretary of the
            Borrower and each of the Guarantors that this First Amendment has
            been duly authorized, executed and delivered by the Borrower and
            each of the Guarantors, such certificate to include a copy of
            corporate resolutions of the Borrower and each of the Guarantors
            authorizing the execution of this First Amendment, incumbency and
            copies of corporate documents;

      (d)   an opinion of counsel to the Borrower and the Guarantors covering
            such matters as the Agent may request (including, without
            limitation, corporate existence and good

                                       9
<PAGE>

            standing, corporate authority, due authorization, execution and
            delivery of the Operative Documents, and the legal, valid, binding
            and enforceable nature of the Operative Documents), such opinion to
            be satisfactory in form and substance to counsel to the Agent; and

      (e)   such other documents and certificates as shall be requested by the
            Agent to effect the intent of this First Amendment.

40.   This First Amendment may be executed in several counterparts and such
      counterparts together shall constitute one and the same instrument.

41.   From the Effective Date, all references in the Operative Agreements to the
      Third Amended and Restated Credit Agreement, dated as of December 15,
      2003, shall mean such Agreement, as amended by this First Amendment.
      Obligations under the Notes and the Agreement are secured in accordance
      with the Security Agreements and the Pledge Agreements.

42.   The Borrower hereby acknowledges, as set forth in the Waiver, that the
      execution of this First Amendment and the Waiver shall not limit the
      Revolving Lenders' ability to declare an Event of Default based upon any
      Securities and Exchange Commission ("SEC") and/or National Association of
      Securities Dealers ("NASD") action subsequent to the date hereof regarding
      any actions of the Borrower and/or any of its Subsidiaries in connection
      with the Insured Deposit Product or the Asserted Violation, including
      without limitation a default under Section 6.1(j) or 6.1(k) of the
      Agreement. For purposes of this First Amendment, "Insured Deposit Product"
      means a certain product that the Borrower offers to its customers that is
      described in the information from the Borrower attached to the Waiver as
      Exhibit A and that was the basis of the SEC and the NASD investigation,
      and "Asserted Violation" means the asserted violation by the Borrower
      based upon the SEC and the NASD's investigation as more specifically
      described in Exhibit A to the Waiver.

                            [Signature page follows]

                                       10
<PAGE>

      IN WITNESS WHEREOF, the Borrower, the Guarantors and the Revolving Lenders
have caused this First Amendment to the Third Amended and Restated Revolving
Credit Agreement to be executed by their duly authorized corporate officers as
of the day and year first above written.

BORROWER:

                                  AMERITRADE HOLDING CORPORATION

                                  By:   /s/ John R. MacDonald
                                        --------------------------------
                                  Name: John R. MacDonald
                                  Title: Executive Vice President, Chief
                                         Financial Officer and Treasurer

GUARANTORS:

                                  AMERITRADE ONLINE HOLDINGS CORP.

                                  By:   /s/ John R. MacDonald
                                        ---------------------------------
                                  Name: John R. MacDonald
                                  Title: Treasurer

                                  DATEK ONLINE HOLDINGS CORP.

                                  By:   /s/ John R. MacDonald
                                        -----------------------------------
                                  Name: John R. MacDonald
                                  Title: Treasurer

                                       11
<PAGE>

REVOLVING LENDERS:

                                  FIRST NATIONAL BANK OF OMAHA

                                  By:   /s/ Mark A. Baratta
                                        ------------------------
                                  Name: Mark A. Baratta
                                  Title: Vice President

                                  LASALLE BANK NATIONAL ASSOCIATION

                                  By:   /s/ David J. Gardner
                                        ------------------------
                                  Name: David J. Gardner
                                  Title: Vice President

                                  M&I MARSHALL & ILSLEY BANK

                                  By:   /s/ Mark P. Schaus
                                        ------------------------
                                  Name: Mark P. Schaus
                                  Title: Vice President

                                  WELLS FARGO BANK, NATIONAL ASSOCIATION

                                  By:   /s/ Daniel A. Toll
                                        --------------------------
                                  Name: Daniel A. Toll
                                  Title: Vice President

                                       12
<PAGE>

                                  ATTACHMENT I
              TO THE FIRST AMENDMENT TO THIRD AMENDED AND RESTATED
                           REVOLVING CREDIT AGREEMENT

                                   APPENDIX I

                          TO THIRD AMENDED AND RESTATED
                           REVOLVING CREDIT AGREEMENT
                                      AMONG
                         AMERITRADE HOLDING CORPORATION,
                                       AND
                     FIRST NATIONAL BANK OF OMAHA, AS AGENT
                                       AND
                         REVOLVING LENDERS PARTY HERETO

                          REVOLVING CREDIT COMMITMENTS

                                       13
<PAGE>

                          REVOLVING CREDIT COMMITMENTS
                         AMERITRADE HOLDING CORPORATION

<TABLE>
<CAPTION>
                           REVOLVING           REVOLVING       AMENDMENT     CLOSING
    LENDER                 COMMITMENT         COMMITMENT %      FEE(1):      FEE(2):
-------------------     ---------------       ------------     ---------     -------
<S>                     <C>                   <C>              <C>           <C>
First National Bank
of Omaha                $    30,000,000           28.6%        $   5,000     $ 5,000

LaSalle Bank National
Association             $    25,000,000           23.8%        $   5,000     $     0

M&I Marshall &
Ilsley Bank             $    25,000,000           23.8%        $   3,000     $10,000

Wells Fargo Bank,
National Association    $    25,000,000           23.8%        $   2,000     $15,000

TOTAL REVOLVING         ---------------
CREDIT COMMITMENT       $105,000,000.00
</TABLE>

Dated as of December 13, 2004.

(1) Amendment fees will be equal to .0002 (2 bps) times the size of the existing
respective Commitment, without giving effect to the First Amendment, as shown
below:

<TABLE>
<CAPTION>
Existing Commitment          Amendment Fee
-------------------          -------------
<S>                          <C>
$10,000,000.00                 $2,000.00

$15,000,000.00                 $3,000.00

$25,000,000.00                 $5,000.00
</TABLE>

(2) Closing fees will be equal to .0010 (10 bps) times the size of the increase
in the respective Commitment as shown below:

<TABLE>
<CAPTION>
Commitment Amount Increase            Closing Fee
--------------------------            -----------
<S>                                   <C>
$ 5,000,000.00                         $ 5,000.00

$10,000,000.00                         $10,000.00

$15,000,000.00                         $15,000.00
</TABLE>

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