Exhibit 10.20

                               September 13, 2005

Ellen L.S. Koplow

     Re: Executive Employment Agreement between Ameritrade Holding Corporation
     ("Ameritrade") and Ellen L.S. Koplow, effective September 9, 2002 (the
     "Agreement")

Dear Ellen:

     Your Agreement has a term ending on September 9, 2005. You and Ameritrade
have agreed to extend the Term of your Agreement for a twelve month period to
September 9, 2006. All of the rights and obligations will continue in full force
and effect through September 9, 2006. For purposes of clarification only, any
right to renew the Agreement was satisfied by the Renewal of the Agreement
effective September 9, 2004 and there is no right to renew the Agreement further
unless agreed upon by both parties in writing, as evidenced by a document
similar to the one herein being signed. Accordingly, Section 6 (e) (vi) of the
Agreement is fully satisfied and is no longer in effect.

     Please indicate your agreement to this extension by signing the letter in
the space below and return one fully signed letter to me. We will countersign
and provide you a copy for your records.

                                        Very truly yours,

                                        AMERITRADE HOLDING CORPORATION


                                        By: /S/ JOE H. MOGLIA
                                            ------------------------------------
                                            Joe H. Moglia
                                            Chief Executive Officer


Understood and Agreed


/S/ ELLEN L.S. KOPLOW
- -------------------------------------
Ellen L.S. Koplow