Exhibit 10.15

                          INSTRUMENT OF AMENDMENT



         INSTRUMENT OF AMENDMENT, effective as of July 27, 2000 (the
"Amendment"), between NATIONAL ASSOCIATION OF SECURITIES DEALERS, INC. (the
"Association") and FRANK G. ZARB ("Zarb") to the employment agreement
effective on February 24, 1997, as amended effective March 18, 1998,
subsequently amended as of August, 1999, and subsequently amended on March
30, 2000, between the Association and Zarb (the "Employment Agreement").


                            W I T N E S S E T H:
                            - - - - - - - - - -


         WHEREAS, the Association and Zarb have entered into the Employment
Agreement;

         WHEREAS, Paragraph 26 of the Employment Agreement provides that
the Employment Agreement may be amended by the mutual consent of the
parties which consent must be evidenced by a document executed with the
same formality as the Employment Agreement;

         WHEREAS, the Association and Zarb wish to modify the Employment
Agreement to provide Zarb with certain further post-retirement benefits in
exchange for his agreement to provide certain post-retirement consulting
services; and

         WHEREAS, the Association and Zarb wish to modify the Employment
Agreement in order to compensate Zarb for any New York state and local
taxes he may incur in connection with the performance of the services
described hereunder in New York City and New York State with respect to his
employment with the Association for the years 1999 and 2000.

         NOW, THEREFORE, it is agreed that the Employment Agreement is
hereby amended in the following manner:

         1.    Subparagraph (b) of Paragraph 5 of the Employment Agreement
               is amended to read, in its entirety, as follows:

                         "(b) Upon completion of the Term and for a period
                  of three years thereafter, the Association shall
                  indemnify and hold Zarb harmless to the fullest extent
                  permitted by applicable law with regard to any action or
                  inaction of Zarb as an officer, director or employee of
                  the Association or as a fiduciary of any benefit plan of
                  the Association; and further upon completion of the Term
                  and for a period of three years thereafter, Zarb shall be
                  entitled to receive at the Association's expense: (i) the
                  full-time and exclusive use of an automobile of his
                  choice and driver, (ii) appropriate office and
                  secretarial services, (iii) payment or reimbursement of
                  dues, initiation and other fees and charges for various
                  clubs in the New York City and/or Washington, D.C.,
                  metropolitan areas upon presentation of appropriate
                  receipts or other documentation (in the case of this
                  clause (iii), not exceeding $20,000 for any year), (iv)
                  upon presentation of appropriate receipts or vouchers in
                  a manner consistent with the expense substantiation
                  policy of the Association generally applicable to its
                  executive officers and in accordance with the provisions
                  of such policy regarding the timing and amount of expense
                  reimbursements, payment or reimbursement of reasonable
                  business-related expenses incurred, including, but not
                  limited to, expenses for such items as entertainment,
                  travel, hotels, and meals, as well as for the travel,
                  hotel, and meals of Zarb's wife on those occasions when
                  the proper representation of the Association makes it
                  advisable for her to accompany him, provided that in the
                  case of travel, hotel, and meals for Zarb's wife, the
                  reimbursements provided under this clause (iv) shall
                  include such amounts as may be necessary for Zarb to pay
                  any taxes imposed with respect to such reimbursements
                  (which amounts shall be paid to Zarb by January 31 of the
                  year following the year in which the expenses were
                  incurred), and (v) to ensure the personal safety of Zarb
                  and his wife, at such times and as reasonably required by
                  the circumstances, the cost of a personal bodyguard for
                  Zarb and his wife and/or surveillance of his personal
                  residence and/or other reasonable method of security; and
                  provided further that Zarb's receipt of the benefits
                  described in this subparagraph (b) shall be contingent
                  upon Zarb's agreement to make himself available to
                  provide the consulting services set forth in subparagraph
                  (c) below."

         2.    The first sentence of Paragraph 10(b) of the Employment
               Agreement is hereby amended to read in its entirety as
               follows:

                         "(b) If Zarb transfers his principal residence
                  from the Washington, D.C., metropolitan area to the New
                  York City metropolitan area in connection with his
                  employment under this Employment Agreement, the
                  Association shall reimburse Zarb for: (i) moving expenses
                  (within the meaning of Section 217(b) of the Internal
                  Revenue Code) incurred in connection with the
                  establishment of his principal residence in the New York
                  City metropolitan area and the establishment of any
                  interim residence in the New York City metropolitan area
                  prior to the establishment of his principal residence;
                  (ii) airfare expenses incurred by Zarb and Zarb's wife in
                  connection with locating and establishing such residences
                  in the New York City metropolitan area; (iii) to ensure
                  his personal safety, the cost of installing a home
                  security system in each such residence (if recommended by
                  an independent security study and provided that such
                  reimbursement shall not exceed $10,000); and (iv) the
                  cost of an appropriate efficiency apartment in the
                  Washington D.C., metropolitan area during the remaining
                  Term."

         3.    Paragraph 11 of the Employment Agreement is hereby amended
               by designating the existing substantive provision therein as
               subparagraph (a), and by adding new subparagraph (b) to read
               as follows:

                         "(b) If any remuneration paid to Zarb by the
                  Association hereunder, or otherwise, is subject to New
                  York state and/or local income taxes for the 1999 and/or
                  2000 calendar year, whether such amount is reported in
                  Zarb's income tax return for the applicable year or
                  whether such New York tax liability is assessed at a
                  later date by the New York state and/or local taxing
                  authorities, the Association shall pay Zarb an additional
                  amount with respect to each such year such that the net
                  amount retained by Zarb in each year, after deduction of
                  any such New York taxes and any United States Federal,
                  state or local income tax or payroll tax on such
                  additional amount, is equal to the gross amount of New
                  York state and local tax imposed upon such remuneration
                  for the applicable year, less: (i) any federal tax
                  savings attributable to the payment of such New York
                  state and local tax for the applicable year, and (ii) any
                  tax credits received by Zarb from the state of his
                  residency as a result of the payment of such New York
                  state and local tax for the applicable year. In providing
                  for the additional amount as set forth in this
                  subparagraph (b), it is the intent of the parties that
                  Zarb be fully reimbursed for any such New York state and
                  local tax liability he may incur in connection with his
                  performance of services to the Association in 1999 and
                  2000, as provided hereunder."

         4.    All of the terms and conditions of the Employment Agreement
               as amended by this Instrument of Amendment shall remain in
               full force and effect throughout the term thereof and, to
               the extent applicable, for three years thereafter.

         IN WITNESS WHEREOF, the corporate party hereto has caused this
Instrument of Amendment to be duly executed and delivered on the date
indicated below, and the individual party hereto has executed and delivered
this Instrument of Amendment on the date indicated below, effective for all
purposes as of July 27, 2000.

                                           NATIONAL ASSOCIATION OF SECURITIES
                                             DEALERS, INC.


_____________________                      By_____________________________
Date                                          Chairman of the Management
                                              Compensation Committee


                                              (Corporate Seal)


---------------------                      -------------------------------
Date                                       Frank G. Zarb