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                                                                   EXHIBIT 10.15

January 16, 2002

Via Hand Delivery

Dear Dave:

We are pleased to offer you employment on an at will basis with Penson Worldwide
Inc. ("PWI") under the following terms, which are subject to approval by our
Board of Directors at its January 22nd meeting and subject to completion of more
specific documentation as required:

      1.    Your title will be Senior Vice President and Chief Financial
            Officer, and you will be generally responsible for the financial
            accounting and regulatory reporting of all of the companies in our
            group. You will also serve as Chief Financial Officer of our US
            regulated entities, and be directly responsible for the financial
            accounting and regulatory reporting of these companies.

      2.    Your base salary will be $200,000 annually, paid semi-monthly. You
            will be entitled to bonus compensation in accordance with our
            general discretionary bonus policy, which is based on our assessment
            of your performance, and on the overall performance of PWI and its
            subsidiaries. For the first year of your employment, the total bonus
            will not be less than $100,000. For subsequent years, bonus payments
            are not guaranteed. Bonus payments are currently made in July and
            January.

      3.    You will be granted options to purchase 200,000 shares of common
            stock in PWI at a price equal to two times the book value of PWI as
            of December 31, 2001. These options will vest 6.25% per quarter, at
            the end of each calendar quarter of your employment and must be
            exercised within ten years of your employment date.

      4.    Based on your expected start date of February 1, 2002, you will be
            covered by our standard group insurance plan as of March 1, 2002. We
            currently pay for employee coverage, and employees pay for their
            dependent coverage. Please refer to the plan documents for
            additional coverage information.

      5.    Based on your expected start date of February 1, 2002, you will be
            eligible to contribute to our 401(k) retirement plan as of April 1,
            2002. It is our current policy to match 50% of employee
            contributions, up to a maximum of 5,000 per year, for employees at
            your

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            compensation level. This is a discretionary policy, based upon our
            assessment of the company's performance and financial condition.

      6.    You will be entitled to four weeks of paid vacation per year,
            subject to normal scheduling limitations.

      7.    If you are terminated for a reason other than cause, you will be
            entitled to severance compensation of three months base salary, plus
            an additional month for each six months of completed employment, up
            to a maximum of six months total severance compensation. If you are
            terminated for cause, you will not be entitled to any severance pay.

      8.    If PWI undergoes a change of beneficial ownership in excess of 50%
            of the outstanding shares in connection with a merger or similar
            transaction, and in the year subsequent to such change, you are
            terminated for a reason other than cause, 50% of any remaining
            unvested options to purchase PWI stock will vest immediately prior
            to such termination.

If these terms are acceptable, please evidence your agreement by signing below.
We look forward to working with you.

Sincerely,

Phil Pendergraft
Chief Operating Officer

Accepted:

David R. Henkel