<PAGE>


                                                                     EXHIBIT 4.5


NEITHER THIS WARRANT NOR THE SHARES ISSUABLE UPON EXERCISE HEREOF HAVE BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT")
OR ANY OTHER APPLICABLE STATE SECURITIES LAWS IN RELIANCE UPON AN EXEMPTION FROM
THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT PURSUANT TO REGULATION D AND
SUCH OTHER SECURITIES LAWS. NEITHER THIS WARRANT NOR THE SHARES ISSUABLE UPON
EXERCISE HEREOF MAY BE SOLD, PLEDGED, TRANSFERRED, ENCUMBERED OR OTHERWISE
DISPOSED OF EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE
SECURITIES ACT OR IN A TRANSACTION WHICH IS EXEMPT FROM REGISTRATION UNDER THE
PROVISIONS OF THE SECURITIES ACT OR ANY APPLICABLE STATE LAWS. THIS WARRANT MAY
NOT BE EXERCISED BY OR ON BEHALF OF A UNITED STATES PERSON UNLESS REGISTERED
UNDER THE SECURITIES ACT OR AN EXEMPTION FROM SUCH REGISTRATION IS AVAILABLE, AS
REQUIRED BY REGULATION D.


                             STOCK PURCHASE WARRANT


                  To Purchase 27,273 Shares of Common Stock of

                             A.B. WATLEY GROUP INC.


         THIS CERTIFIES that, for value received, Keefe Bruyette & Woods, Inc.
(the "Holder") is entitled, upon the terms and subject to the limitations on
exercise and the conditions hereinafter set forth, at any time on or after the
date hereof (the "Initial Exercise Date") and on or prior to the close of
business on April 1, 2004 (the "Termination Date") but not thereafter, to
subscribe for and purchase from A.B. Watley Group Inc., a corporation
incorporated in the State of Delaware (the "Company"), up to 27,273 shares (the
"Warrant Shares") of Common Stock, $0.001 par value, of the Company (the "Common
Stock"). The purchase price of one share of Common Stock (the "Exercise Price")
under this Warrant shall be $6.75. The Exercise Price and the number of shares
for which the Warrant is exercisable shall be subject to adjustment as provided
herein. In the event of any conflict between the terms of this Warrant and the
Stock Purchase Agreement, dated as of March 29, 2001, pursuant to which this
Warrant has been issued (the "Purchase Agreement"), the Purchase Agreement shall
control. Capitalized terms used and not otherwise defined herein shall have the
meanings set forth for such terms in the Purchase Agreement.

         1. Title to Warrant. Prior to the Termination Date and subject to
compliance with applicable laws, this Warrant and all rights hereunder are
transferable, in


<PAGE>

whole or in part, at the office or agency of the Company by the Holder hereof in
person or by duly authorized attorney, upon surrender of this Warrant together
with the Assignment Form annexed hereto properly endorsed.

         2. Authorization of Shares. The Company covenants that all shares of
Common Stock which may be issued upon the exercise of the purchase rights
represented by this Warrant will, upon exercise of the purchase rights
represented by this Warrant, be duly authorized, validly issued, fully paid and
nonassessable and free from all taxes, liens and charges in respect of the issue
thereof (other than taxes in respect of any transfer occurring contemporaneously
with such issue).

         3. Exercise of Warrant.

                  (a) Exercise of the purchase rights represented by this
Warrant may be made at any time or times on or after the Initial Exercise Date,
and before the close of business on the Termination Date by the surrender of
this Warrant and the Notice of Exercise annexed hereto duly executed, at the
office of the Company (or such other office or agency of the Company as it may
designate by notice in writing to the registered Holder hereof at the address of
such Holder appearing on the books of the Company) and upon payment of the
Exercise Price of the shares thereby purchased by wire transfer or cashier's
check drawn on a United States bank, the Holder of this Warrant shall be
entitled to receive a certificate for the number of shares of Common Stock so
purchased. Certificates for shares purchased hereunder shall be delivered to the
Holder hereof within three (3) Business Days after the date on which this
Warrant shall have been exercised as aforesaid. This Warrant shall be deemed to
have been exercised and such certificate or certificates shall be deemed to have
been issued, and Holder or any other person so designated to be named therein
shall be deemed to have become a holder of record of such shares for all
purposes, as of the date the Warrant has been exercised by payment to the
Company of the Exercise Price and all taxes required to be paid by Holder, if
any, pursuant to Section 5 prior to the issuance of such shares, have been paid.

                  (b) If this Warrant shall have been exercised in part, the
Company shall, at the time of delivery of the certificate or certificates
representing Warrant Shares, deliver to Holder a new Warrant evidencing the
rights of Holder to purchase the unpurchased shares of Common Stock called for
by this Warrant, which new Warrant shall in all other respects be identical with
this Warrant.

                  (a) If no registration statement is effective permitting the
resale of the shares of Common Stock issued upon exercise of this Warrant at any
time commencing one year after the issuance date hereof, then this Warrant shall
also be exercisable by means of a "cashless exercise" in which the Holder shall
be entitled to receive a certificate for the number of shares equal to the
quotient obtained by dividing [(A-B) (X)] by (A), where:

(A) = the average of the high and low trading prices per share of Common Stock
on the Business Day preceding the date of such election on the Nasdaq Stock
Market, or if the



                                       2

<PAGE>

Common Stock is not traded on the Nasdaq Stock Market, then the Principal Market
in terms of volume, and converted into US Dollars;
(B) = the Exercise Price of the Warrants; and
(X) = the number of shares issuable upon
exercise of the Warrants in accordance with the terms of this Warrant.

         4. No Fractional Shares or Scrip. No fractional shares or scrip
representing fractional shares shall be issued upon the exercise of this
Warrant. As to any fraction of a share which Holder would otherwise be entitled
to purchase upon such exercise, the Company shall pay a cash adjustment in
respect of such final fraction in an amount equal to the Exercise Price.

         5. Charges, Taxes and Expenses. Issuance of certificates for shares of
Common Stock upon the exercise of this Warrant shall be made without charge to
the Holder hereof for any issue or transfer tax or other incidental expense in
respect of the issuance of such certificates, all of which taxes and expenses
shall be paid by the Company, and such certificates shall be issued in the name
of the Holder of this Warrant or in such name or names as may be directed by the
Holder of this Warrant; provided, however, that in the event certificates for
shares of Common Stock are to be issued in a name other than the name of the
Holder of this Warrant, this Warrant when surrendered for exercise shall be
accompanied by the Assignment Form attached hereto duly executed by the Holder
hereof; and the Company may require, as a condition thereto, the payment of a
sum sufficient to reimburse it for any transfer tax incidental thereto.

         6. Closing of Books. The Company will not close its stockholder books
or records in any manner which prevents the timely exercise of this Warrant.

         7. Transfer, Division and Combination. (a) Subject to compliance with
any applicable securities laws, transfer of this Warrant and all rights
hereunder, in whole or in part, shall be registered on the books of the Company
to be maintained for such purpose, upon surrender of this Warrant at the
principal office of the Company, together with a written assignment of this
Warrant substantially in the form attached hereto duly executed by Holder or its
agent or attorney and funds sufficient to pay any transfer taxes payable upon
the making of such transfer. Upon such surrender and, if required, such payment,
the Company shall execute and deliver a new Warrant or Warrants in the name of
the assignee or assignees and in the denomination or denominations specified in
such instrument of assignment, and shall issue to the assignor a new Warrant
evidencing the portion of this Warrant not so assigned, and this Warrant shall
promptly be cancelled. A Warrant, if properly assigned, may be exercised by a
new holder for the purchase of shares of Common Stock without having a new
Warrant issued.

(b) This Warrant may be divided or combined with other Warrants upon
presentation hereof at the aforesaid office of the Company, together with a
written notice specifying the names and denominations in which new Warrants are
to be issued, signed by Holder or its agent or attorney. Subject to compliance
with Section 7(a), as to any transfer which may be involved in such division or
combination, the Company shall



                                       3

<PAGE>

execute and deliver a new Warrant or Warrants in exchange for the Warrant or
Warrants to be divided or combined in accordance with such notice.

(c) The Company shall prepare, issue and deliver at its own expense (other than
transfer taxes) the new Warrant or Warrants under this Section 7.

(d) The Company agrees to maintain, at its aforesaid office, books for the
registration and the registration of transfers of the Warrants.

         8. No Rights as Stockholder until Exercise. This Warrant does not
entitle the Holder hereof to any voting rights or other rights as a stockholder
of the Company prior to the exercise hereof. Upon the surrender of this Warrant
and the payment of the aggregate Exercise Price, the Warrant Shares so purchased
shall be and be deemed to be issued to such Holder as the record owner of such
shares as of the close of business on the later of the date of such surrender or
payment.

         9. Loss, Theft, Destruction or Mutilation of Warrant. The Company
covenants that upon receipt by the Company of evidence reasonably satisfactory
to it of the loss, theft, destruction or mutilation of this Warrant certificate
or any stock certificate relating to the Warrant Shares, and in case of loss,
theft or destruction, of indemnity or security reasonably satisfactory to it
(which shall not include the posting of any bond), and upon surrender and
cancellation of such Warrant or stock certificate, if mutilated, the Company
will make and deliver a new Warrant or stock certificate of like tenor and dated
as of such cancellation, in lieu of such Warrant or stock certificate.

         10. Saturdays, Sundays, Holidays, etc. If the last or appointed day for
the taking of any action or the expiration of any right required or granted
herein shall be a Saturday, Sunday or a legal holiday, then such action may be
taken or such right may be exercised on the next succeeding day not a Saturday,
Sunday or legal holiday.

         11. Adjustments of Exercise Price and Number of Warrant Shares.

                  a. Stock Splits, etc. The number and kind of securities
purchasable upon the exercise of this Warrant and the Exercise Price shall be
subject to adjustment from time to time upon the happening of any of the
following. In case the Company shall (i) pay a dividend in shares of Common
Stock or make a distribution in shares of Common Stock to holders of its
outstanding Common Stock, (ii) subdivide its outstanding shares of Common Stock
into a greater number of shares of Common Stock, (iii) combine its outstanding
shares of Common Stock into a smaller number of shares of Common Stock or (iv)
issue any shares of its capital stock in a reclassification of the Common Stock,
then the number of Warrant Shares purchasable upon exercise of this Warrant
immediately prior thereto shall be adjusted so that the Holder of this Warrant
shall be entitled to receive the kind and number of Warrant Shares or other
securities of the Company which he would have owned or have been entitled to
receive had such Warrant been exercised in advance thereof. Upon each such
adjustment of the kind and number of Warrant Shares or other securities of the
Company which are purchasable



                                       4

<PAGE>

hereunder, the Holder of this Warrant shall thereafter be entitled to purchase
the number of Warrant Shares or other securities resulting from such adjustment
at an Exercise Price per Warrant Share or other security obtained by multiplying
the Exercise Price in effect immediately prior to such adjustment by the number
of Warrant Shares purchasable pursuant hereto immediately prior to such
adjustment and dividing by the number of Warrant Shares or other securities of
the Company resulting from such adjustment. An adjustment made pursuant to this
paragraph shall become effective immediately after the effective date of such
event retroactive to the record date, if any, for such event.

                  b. Reorganization, Merger, Consolidation or Disposition of
Assets. In case the Company shall reorganize its capital, merge or consolidate
with or into another corporation (where the Company is not the surviving
corporation or where there is a change in or distribution with respect to the
Common Stock of the Company), or sell, transfer or otherwise dispose of all or
substantially all its property, assets or business to another corporation and,
pursuant to the terms of such reorganization, merger, consolidation or sale,
transfer or disposition of assets, shares of common stock of the successor or
acquiring corporation, or any cash, shares of stock or other securities or
property of any nature whatsoever (including warrants or other subscription or
purchase rights) in addition to or in lieu of common stock of the successor or
acquiring corporation ("Other Property"), are to be received by or distributed
to the holders of Common Stock of the Company, then Holder shall have the right
thereafter to receive, upon exercise of this Warrant, the number of shares of
common stock of the successor or acquiring corporation or of the Company, if it
is the surviving corporation, and Other Property receivable upon or as a result
of such reorganization, merger, consolidation, sale, transfer or disposition of
assets by a Holder of the number of shares of Common Stock for which this
Warrant is exercisable immediately prior to such event. In case of any such
reorganization, merger, consolidation, sale, transfer or disposition of assets,
the successor or acquiring corporation (if other than the Company) shall
expressly assume the due and punctual observance and performance of each and
every covenant and condition of this Warrant to be performed and observed by the
Company and all the obligations and liabilities hereunder, subject to such
modifications as may be deemed appropriate (as determined in good faith by
resolution of the Board of Directors of the Company) in order to provide for
adjustments of shares of Common Stock for which this Warrant is exercisable
which shall be as nearly equivalent as practicable to the adjustments provided
for in this Section 11. For purposes of this Section 11, "common stock of the
successor or acquiring corporation" shall include stock of such corporation of
any class which is not preferred as to dividends or assets over any other class
of stock of such corporation and which is not subject to redemption and shall
also include any evidences of indebtedness, shares of stock or other securities
which are convertible into or exchangeable for any such stock, either
immediately or upon the arrival of a specified date or the happening of a
specified event, and any warrants or other rights to subscribe for or purchase
any such stock. The foregoing provisions of this Section 11 shall similarly
apply to successive reorganizations, mergers, consolidations, sales, transfers
or dispositions of assets.

                  12. Voluntary Adjustment by the Company. The Company may at
any time during the term of this Warrant, reduce the then current Exercise Price
to any



                                       5

<PAGE>

amount and for any period of time deemed appropriate by the Board of Directors
of the Company.

         13. Notice of Adjustment. Whenever the number of Warrant Shares or
number or kind of securities or other property purchasable upon the exercise of
this Warrant or the Exercise Price is adjusted, as herein provided, the Company
shall promptly mail by registered or certified mail, return receipt requested,
to the Holder of this Warrant notice of such adjustment or adjustments setting
forth the number of Warrant Shares (and other securities or property)
purchasable upon the exercise of this Warrant and the Exercise Price of such
Warrant Shares (and other securities or property) after such adjustment, setting
forth a brief statement of the facts requiring such adjustment and setting forth
the computation by which such adjustment was made. Such notice, in the absence
of manifest error, shall be conclusive evidence of the correctness of such
adjustment.

         14. Notice of Corporate Action. If at any time:

      (a) the Company shall take a record of the holders of its Common Stock for
the purpose of entitling them to receive a dividend or other distribution, or
any right to subscribe for or purchase any evidences of its indebtedness, any
shares of stock of any class or any other securities or property, or to receive
any other right; or

      (b) there shall be any capital reorganization of the Company, any
reclassification or recapitalization of the capital stock of the Company or any
consolidation or merger of the Company with, or any sale, transfer or other
disposition of all or substantially all the property, assets or business of the
Company to, another corporation; or

      (c) there shall be a voluntary or involuntary dissolution, liquidation or
winding up of the Company;

then, in any one or more of such cases, the Company shall give to Holder (i) at
least 30 days' prior written notice of the date on which a record date shall be
selected for such dividend, distribution, right to subscribe or right or for
determining rights to vote in respect of any such reorganization,
reclassification, recapitalization, consolidation, merger, sale, transfer,
disposition, dissolution, liquidation or winding up, and (ii) in the case of any
such reorganization, reclassification, recapitalization, consolidation, merger,
sale, transfer, disposition, dissolution, liquidation or winding up, at least 30
days' prior written notice of the date when the same shall take place. Such
notice in accordance with the foregoing clause also shall specify (i) the date
on which any such record is to be taken for the purpose of such dividend,
distribution or right, the date on which the holders of Common Stock shall be
entitled to any such dividend, distribution or right, and the amount and
character thereof, and (ii) the date on which any such reorganization,
reclassification, recapitalization, consolidation, merger, sale, transfer,
disposition, dissolution, liquidation or winding up is to take place and the
time, if any such time is to be fixed, as of which the holders of Common Stock
shall be entitled to exchange their shares of Common Stock for securities or
other property deliverable upon such



                                       6

<PAGE>

disposition, dissolution, liquidation or winding up. Each such written notice
shall be sufficiently given if addressed to Holder at the last address of Holder
appearing on the books of the Company and delivered in accordance with Section
16(d).

         15. Authorized Shares. The Company covenants that during the period the
Warrant is outstanding, it will reserve from its authorized and unissued Common
Stock a sufficient number of shares to provide for the issuance of the Warrant
Shares upon the exercise of any purchase rights under this Warrant. The Company
further covenants that its issuance of this Warrant shall constitute full
authority to its officers who are charged with the duty of executing stock
certificates to execute and issue the necessary certificates for the Warrant
Shares upon the exercise of the purchase rights under this Warrant. The Company
will take all such reasonable action as may be necessary to assure that such
Warrant Shares may be issued as provided herein without violation of any
applicable law or regulation, or of any requirements of the Principal Market
upon which the Common Stock may be listed.

         The Company shall not by any action, including, without limitation,
amending its certificate of incorporation or through any reorganization,
transfer of assets, consolidation, merger, dissolution, issue or sale of
securities or any other voluntary action, avoid or seek to avoid the observance
or performance of any of the terms of this Warrant, but will at all times in
good faith assist in the carrying out of all such terms and in the taking of all
such actions as may be necessary or appropriate to protect the rights of Holder
against impairment. Without limiting the generality of the foregoing, the
Company will (a) not increase the par value of any shares of Common Stock
receivable upon the exercise of this Warrant above the amount payable therefor
upon such exercise immediately prior to such increase in par value, (b) take all
such action as may be necessary or appropriate in order that the Company may
validly and legally issue fully paid and nonassessable shares of Common Stock
upon the exercise of this Warrant, and (c) use commercially reasonable efforts
to obtain all such authorizations, exemptions or consents from any public
regulatory body having jurisdiction thereof as may be necessary to enable the
Company to perform its obligations under this Warrant.

Before taking any action which would result in an adjustment in the number of
shares of Common Stock for which this Warrant is exercisable or in the Exercise
Price, the Company shall obtain all such authorizations or exemptions thereof,
or consents thereto, as may be necessary from any public regulatory body or
bodies having jurisdiction thereof.

         16. Miscellaneous.

                  a. Jurisdiction. This Warrant shall be binding upon any
successors or assigns of the Company. This Warrant shall constitute a contract
under the laws of New York, without regard to its conflict of law principles or
rules, and be subject to arbitration pursuant to the terms set forth in the
Purchase Agreement.



                                       7

<PAGE>

                  b. Restrictions. The Holder hereof acknowledges that the
Warrant Shares acquired upon the exercise of this Warrant, if not registered,
will have restrictions upon resale imposed by state and federal securities laws.

                  c. Nonwaiver and Expenses. No course of dealing or any delay
or failure to exercise any right hereunder on the part of Holder shall operate
as a waiver of such right or otherwise prejudice Holder's rights, powers or
remedies, notwithstanding all rights hereunder terminate on the Termination
Date. If the Company willfully fails to comply with any provision of this
Warrant, the Company shall pay to Holder such amounts as shall be sufficient to
cover any costs and expenses including, but not limited to, reasonable
attorneys' fees, including those of appellate proceedings, incurred by Holder in
collecting any amounts due pursuant hereto or in otherwise enforcing any of its
rights, powers or remedies hereunder.

                  d. Notices. Any notice, request or other document required or
permitted to be given or delivered to the Holder hereof by the Company shall be
delivered in accordance with the notice provisions of the Purchase Agreement.

                  e. Limitation of Liability. No provision hereof, in the
absence of affirmative action by Holder to purchase shares of Common Stock, and
no enumeration herein of the rights or privileges of Holder hereof, shall give
rise to any liability of Holder for the purchase price of any Common Stock or as
a stockholder of the Company, whether such liability is asserted by the Company
or by creditors of the Company.

                  f. Remedies. Holder, in addition to being entitled to exercise
all rights granted by law, including recovery of damages, will be entitled to
specific performance of its rights under this Warrant. The Company agrees that
monetary damages would not be adequate compensation for any loss incurred by
reason of a breach by it of the provisions of this Warrant and hereby agrees to
waive the defense in any action for specific performance that a remedy at law
would be adequate.

                  g. Successors and Assigns. Subject to applicable securities
laws, this Warrant and the rights and obligations evidenced hereby shall inure
to the benefit of and be binding upon the successors of the Company and the
successors and permitted assigns of Holder. The provisions of this Warrant are
intended to be for the benefit of all Holders from time to time of this Warrant
and shall be enforceable by any such Holder or holder of Warrant Shares.

                  h. Indemnification. The Company agrees to indemnify and hold
harmless Holder from and against any liabilities, obligations, losses, damages,
penalties, actions, judgments, suits, claims, costs, reasonable attorneys' fees,
expenses and disbursements of any kind which may be imposed upon, incurred by or
asserted against Holder in any manner relating to or arising out of any failure
by the Company to perform or observe in any material respect any of its
covenants, agreements, undertakings or obligations set forth in this Warrant;
provided, however, that the Company will not be liable hereunder to the extent
that any liabilities, obligations, losses, damages, penalties,



                                       8

<PAGE>

actions, judgments, suits, claims, costs, attorneys' fees, expenses or
disbursements are found in a final non-appealable judgment by a court to have
resulted from Holder's negligence, bad faith or willful misconduct in its
capacity as a stockholder or warrantholder of the Company.

                  i. Amendment. This Warrant may be modified or amended or the
provisions hereof waived with the written consent of the Company and the Holder.

                  j. Severability. Wherever possible, each provision of this
Warrant shall be interpreted in such manner as to be effective and valid under
applicable law, but if any provision of this Warrant shall be prohibited by or
invalid under applicable law, such provision shall be ineffective to the extent
of such prohibition or invalidity, without invalidating the remainder of such
provisions or the remaining provisions of this Warrant.

                  k. Headings. The headings used in this Warrant are for the
convenience of reference only and shall not, for any purpose, be deemed a part
of this Warrant.

         IN WITNESS WHEREOF, the Company has caused this Warrant to be executed
by its officer thereunto duly authorized.


Dated: April 2, 2001



                             A.B. WATLEY GROUP INC.

                                          By:  /s/ Steven Malin
                                               ----------------
                                                Steven Malin, Chairman and CEO



                                       9