<PAGE>   1
                                                                    EXHIBIT 10.2
                              EMPLOYMENT AGREEMENT

     EMPLOYMENT AGREEMENT, dated January 3,2001 between Ameritrade Holding
Corporation (the "Corporation"), and James M. Ditmore (the "Executive").

                                    RECITALS

     The Corporation desires to assure to the Corporation the benefits of the
Executive's expertise and knowledge, and the Executive, in turn, desires
full-time, at-will employment with the Corporation, on the terms provided in
this Agreement.

     Accordingly, in consideration of the mutual agreements contained in this
Agreement, the parties agree as follows:

                                    ARTICLE I

                        FULL-TIME EMPLOYMENT OF EXECUTIVE

     1.1 DUTIES AND STATUS.

         (a) Titles, Authority and Reporting. The Corporation hereby continues
the employment relationship of Executive as a full-time, at-will employee,
effective as January 3, 2001, and the Executive accepts such employment, on the
terms and conditions set forth in this Agreement. During his employment with the
Corporation, the Executive shall hold such titles (presently, Chief Information
Officer), shall exercise such authority and shall perform such executive duties
as are assigned to him by the Chairman of the Board of the Corporation or his
designee. The Executive shall report to the Chief Executive Officer of the
Corporation or to such other individual designated by the Chairman of the Board
of the Corporation.

         (b) Full-time Efforts. During his employment with the Corporation, the
Executive shall devote his full professional time and efforts to the business of
the Corporation and will not engage in consulting work or any trade or business
of his own account or for or on behalf of any other individual or entity.

         (c) Inability to Perform. During his employment with the Corporation,
the Executive shall be entitled to vacation and leave for illness or temporary
disability in accordance with the Corporation's policies for its senior
executive officers. Any leave on account of illness or temporary disability
which is short of a long term disability (as determined by the Corporation in
its discretion) shall not constitute a breach of this Agreement by the
Executive, but leave on account of a long term disability (as determined by the
Corporation in its discretion) shall be deemed to result in a voluntary
termination by the Executive of the Executive's employment with the Corporation.

         (d) Guidelines and Laws. During his employment with the Corporation,
the Executive shall at all times comply with the Corporation's Equity Ownership
and Disposition Guidelines (which currently generally require the Executive to
own Corporation stock valued at




                                       1
<PAGE>   2

two (2) times the Executive's base salary) no later than January 31, 2004. In
addition, during his employment with the Corporation, the Executive shall at all
times comply with all applicable Corporation policies and all applicable
federal, state and local laws.

         (e) Assistance with Claims. During his employment with the Corporation,
and for a reasonable time thereafter, the Executive will provide reasonable
assistance to the Corporation and/or its affiliates in defense or prosecution of
claims against or by the Corporation and/or its affiliates, to the extent that
the Executive has knowledge or information that, in the judgment of the
Corporation, could be of such assistance. The Corporation shall reimburse the
Executive for any reasonable out-of-pocket expenses associated with such
assistance.

     1.2 COMPENSATION AND GENERAL BENEFITS. As compensation for his services
under this Agreement, the Executive shall be compensated as follows:

         (a) Base Salary. Executive's current base salary is $350,000 per year,
payable on the Corporation's regular schedule for executive pay. The Executive's
base salary is subject to review and adjustment from time-to-time as deemed
appropriate by the Board of the Corporation or its designee.

         (b) Benefit Programs. During his employment with the corporation, the
Executive shall be entitled to participate in the Corporation's employee benefit
programs generally available to its senior executive employees, pursuant to the
terms of those programs. The Corporation retains the right to terminate or amend
these programs from time-to-time as it deems appropriate.

         The compensation and benefit programs in which the Executive shall
participate on January 3, 2001 include, but are not limited to, the following:

         1.  Incentive Bonus. The Executive is eligible to receive an annual
incentive bonus, payable at the same time as other executives, in accordance
with all of the terms of the Corporation's annual incentive bonus program. This
program provides for a threshold bonus of thirty percent (30%) of base salary, a
targeted bonus of sixty percent (60%) of base salary, and a maximum bonus of
ninety percent (90%) of base salary, with no bonus paid for performance below
the threshold.

         2.  Nonqualified  Stock  Options.  The Executive will be eligible for
stock option grants at the discretion of the Compensation Committee of the Board
of Directors.

         Subject to Compensation Committee approval, the Executive's unvested
         stock options will vest in the event the Executive's employment is
         terminated other than "for cause" (as defined in Section 4.2 (C)
         within 6 months following a change of control. For this purpose,
         change of control means (A) the completion of a plan of complete
         liquidation of the Corporation which has been approved by the
         Corporation's shareholders, (B) the sale or disposition by the
         Corporation of all or substantially all of the assets of the
         Corporation (or any transaction having a similar effect), or (C) the
         consummation of a merger or consolidation of the Corporation with any
         other Corporation, other than (i) a merger or consolidation




                                       2
<PAGE>   3

         which would result in the voting securities of the Corporation
         outstanding immediately prior thereto continuing to represent (either
         by remaining outstanding or by being converted into voting securities
         of the surviving entity) more than 50% of the combined voting power of
         the voting securities of the Corporation or such surviving entity
         outstanding immediately after such merger or consolidation (ii) a
         merger or consolidation effected to implement a recapitalization of
         the Corporation (or similar transaction).

         No unvested stock options will vest upon the Executive's termination of
employment, except as indicated above with respect to a change of control.


         3. Paid Time  Off/Vacation.  The Executive is entitled to paid time off
and Corporation  holidays in an amount in accordance with Ameritrade's Corporate
Policy.

         4. Deferred Compensation Program. The Executive will be eligible to
participate in the Corporation's Deferred Compensation Program in accordance
with its terms and conditions.

                                   ARTICLE II

               COMPETITION; CONFIDENTIAL INFORMATION; SOLICITATION

     2.1 COMPETITION; CONFIDENTIAL INFORMATION. The Executive and the
Corporation recognize that, due to the nature of his employment with the
Corporation, the Executive will have access to and will acquire, and may assist
in developing, confidential and proprietary information relating to the business
and operations of the Corporation and its affiliates, including, without
limiting the generality of the foregoing, information with respect to the
Corporation's present systems, customers, agents, accounts, deposits, loans,
sales and marketing methods, and those items listed as confidential or private
in the Ameritrade, Inc. Technology Group Agreement.

         The Executive acknowledges that such information is of central
importance to the business of the Corporation and its affiliates and that
disclosure of it to or its use by others could cause substantial loss to the
Corporation and its affiliates. The Executive and the Corporation also recognize
that an important part of the Executive's duties will be to develop good will
for the Corporation and its affiliates through his personal contact with
customers, agents and others sharing business relationships with the Corporation
and its affiliates, and that there is a danger that this good will, a
proprietary asset of the Corporation and its affiliates, may follow the
Executive if and when his relationship with the Corporation is terminated.

         The Executive accordingly agrees as follows:

         (a) Non-Competition. During his employment with the Corporation, and
thereafter for the longer of twenty-four (24) months or for any period during
which or with respect to which payments of compensation are being made to the
Executive under this Agreement





                                       3
<PAGE>   4

or any severance type program of the Corporation, the Executive will not,
directly or indirectly, either individually or as owner, partner, agent,
employee, consultant or otherwise engage in any activity competitive with the
business of the Corporation and its affiliates.


         (b) Passive Ownership. Nothing in this Article II shall be construed to
prevent the Executive from owning, as an entirely passive investment, not more
than ten percent (10%) of a class of equity securities issued by any issuer
whose business is in no way competitive with the business of the Corporation.

         The Executive also represents that he is not now a party to any
agreement restricting or purporting to restrict his right to perform any of the
services contemplated by this Agreement.

         This Section 2.1 shall survive the termination of this Agreement.

     2.2 NON-DISCLOSURE. During and at all times after the date of this
Agreement, the Executive will keep confidential any confidential or proprietary
information of the Corporation and its affiliates which is now known to him or
which becomes known to him as a result of his employment or association with the
Corporation and its affiliates and shall not at any time directly or indirectly
disclose any such information to any individual or entity or use the same in any
way other than in connection with the business of the Corporation and its
affiliates. For purposes of this Agreement, "confidential or proprietary
information" means information unique to the Corporation and/or its affiliates
which has a significant business purpose and is not known or generally available
from sources outside the Corporation and its affiliates or typical of industry
practice, and includes those items listed as confidential or private in the
Ameritrade, Inc. Technology Group Agreement. This Section 2.2 shall survive the
termination of this Agreement.

     2.3 NON-SOLICITATION. During and at all times after the date of this
Agreement, the Executive will not, without the express written consent of the
Corporation, solicit any individual who is an employee of the Corporation or any
of its affiliates to terminate his or her employment with the Corporation or its
affiliate. This Section 2.3 shall survive the termination of this Agreement.

                                   ARTICLE III

                 CORPORATION'S REMEDIES FOR BREACH OF ARTICLE II

     3.1 CORPORATION'S REMEDIES FOR BREACH. It is recognized that damages in the
event of a breach of Article II by the Executive would be difficult, if not
impossible, to ascertain, and it is therefore agreed that, if such a breach
occurs, the Corporation, in addition to and without limiting any other remedy or
right it may have, shall have the right to an injunction or other equitable
relief, in any court of competent jurisdiction, enjoining any such breach, and
the Executive hereby waives any and all defenses he may have on the ground of
lack of jurisdiction or competence of the court to grant such an injunction or
other equitable relief. The






                                       4
<PAGE>   5

existence of this right shall not preclude any other rights and remedies at law
or in equity which the Corporation may have. The Corporation also shall have the
specific right to a refund of any payments made, but not owed, to the Executive
because of a breach by him of his obligations hereunder, and the Corporation
shall have the right to cease payments not payable to the Executive because of a
breach hereunder.


                                   ARTICLE IV

                               AT-WILL EMPLOYMENT

     4.1 AT-WILL EMPLOYMENT. The Corporation or the Executive may terminate the
Executive's employment with the Corporation, at any time, for any reason.

     4.2 PAYMENTS AFTER EMPLOYMENT PERIOD.

         (a) Involuntary Termination Without Cause. If the Corporation
terminates the Executive's employment for reasons other than "for cause", in
addition to any benefits to which the Executive may be entitled under any of the
Corporation's employee benefit programs, the Corporation may pay the Executive a
severance allowance, subject to the Executive entering into a general release
acceptable to the Corporation in its discretion. This severance allowance shall
be the continuation of the Executive's base salary, at the rate in effect on the
date of termination, for the twelve (12) month period following termination.
This severance allowance shall be reduced by any payments due to the Executive
under any other severance program of the Corporation.

         (b) Change of Control Terminations. If the Corporation terminates the
Executive's employment with the Corporation other than for cause within six
months after a change of control (as defined in Section 1.2), in addition to any
benefits to which the Executive may be entitled under any of the Corporation's
employee benefit programs, the Corporation will pay the Executive a severance
allowance, subject to the Executive entering into a general release acceptable
to the Corporation in its discretion. This severance allowance shall be the
continuation of the Executive's base salary, at the rate in effect on the date
of termination, for the twelve (12) month period following termination. This
severance allowance shall be reduced by any payments due to the Executive under
any other severance program of the Corporation.

         (c) Other Terminations. If the Executive's employment with the
Corporation terminates other than as described in (a) or (b) above, the
Executive, or the Executive's dependents, beneficiaries and estate, as the case
may be, will receive any termination benefits, including but not limited to
health care continuation benefits, as they may be entitled under the terms of
the Corporation's employee benefit programs in which the Executive participated
on the date of his termination which provide benefits upon the applicable type
of termination.

         For purposes of this Section 4.2, the term "for cause" means the
Executive's failure to perform under this Agreement, including but not limited
to embezzlement, fraud, perjury,




                                       5
<PAGE>   6

alteration of documents, robbery, any felonious acts, substantial
non-performance and any conduct that the Corporation determines would compromise
the Corporation's interests.


                                    ARTICLE V

                                     NOTICES

     5.1 NOTICES. Any notices, requests, demands and other communications
provided for by this Agreement shall be sufficient if in writing and if sent by
registered or certified mail to the Executive at the last address he has filed
in writing with the Corporation or, in the case of the Corporation, at its
principal executive offices.


                                   ARTICLE VI

                          ENTIRE AGREEMENT; AMENDMENTS

     6.1 ENTIRE AGREEMENT; AMENDMENTS. This Agreement constitutes the entire
understanding of the Executive and the Corporation with respect to the subject
matter of this Agreement and supersedes any and all prior understandings on the
subjects matter of this Agreement, written or oral. This Agreement may not be
changed, modified or discharged orally, but only by an instrument in writing
signed by the parties. The invalidity or unenforceability of any provisions of
this Agreement shall in no way affect the validity or enforceability of any
other provision of this Agreement.


                                  ARTICLE VII

                               DISPUTE RESOLUTION

     7.1 DISPUTE RESOLUTION. In the event of any dispute, claim, question or
disagreement arising from or relating to this Agreement or its breach, the
parties shall use their best efforts to settle the dispute, claim, question or
disagreement. To this effect, they shall consult and negotiate with each other
in good faith and, recognizing their mutual interests, attempt to reach a just
and equitable solution satisfactory to both parties.

     If they do not reach such a solution within 30 days, the parties agree that
any and all disputes, claims, questions or disagreements arising out of or
related to this Agreement shall be submitted to mediation. Either party may
commence mediation by providing the other party with a written request for
mediation, setting forth the subject of the dispute and the relief requested.
The parties will cooperate with one another in selecting a mediator, and in
scheduling the mediation proceedings. If the parties cannot agree on a mediator,
the parties agree that they shall appoint JAMS/Endispute as a mediation body.
The mediation shall be conducted in accordance with JAMS/Endispute's applicable
employment mediation rules and procedures then in effect. The parties agree that
they shall share equally in the costs of any mediation.





                                       6
<PAGE>   7
     If the parties cannot reach a mutually satisfactory resolution by
mediation, any unresolved disputes, claims, questions or disagreements between
them, including any controversy or claim arising out of or relating to this
Agreement (or its breach) shall be settled by final, binding and non-appealable
arbitration in Omaha, Nebraska by one arbitrator. The arbitration shall be
conducted by JAMS/Endispute or its successor in interest in accordance with its
applicable employment arbitration rules and procedures then in effect. The
arbitrator will be chosen from JAMS/Endispute's panel of former judges. Judgment
upon the award rendered in any arbitration may be entered in any court having
jurisdiction.

     Except as noted below, during the pendency of this dispute resolution
process, the parties agree to forbear from filing or otherwise proceeding with
litigation. Any and all proceedings, hearings, findings or any other record of a
dispute under this Article shall be private and shall be held in the strictest
confidence of all parties so involved, including but not limited to the parties
to this Agreement and any appointed mediator or arbitrator.

     Finally, this Article shall not be construed to limit the Corporation's
right to obtain relief under Article 3 with respect to any matter or controversy
subject to Article 3, and, pending a final determination by the arbitrator with
respect to any such matter or controversy, the Corporation shall be entitled to
obtain any such relief by direct application to a court of law, without being
required to first arbitrate such matter or controversy.

     The provisions of this Article may be enforced by any court of competent
jurisdiction, and the party seeking enforcement shall be entitled to an award of
all costs, fees and expenses, including reasonable attorneys fees, to be paid by
the party against whom enforcement is ordered.

     IN WITNESS WHEREOF, the parties have executed and delivered this Agreement
effective as of January 3, 2001.

ATTEST/WITNESS:                             THE CORPORATION


/s/ John R. MacDonald                       /s/ John Joe Ricketts         (SEAL)
------------------------------------        ------------------------------------

Print Name: John R. MacDonald               Print Name: J. Joe Ricketts
            ------------------------                    ------------------------





/s/ John R. MacDonald                       /s/ James Ditmore             (SEAL)
------------------------------------        ------------------------------------
                                            James M. Ditmore
Print Name: John R. MacDonald
            ------------------------






                                       7