<PAGE>   1
                                                                     EXHIBIT 4.2


                             PENSON WORLDWIDE, INC.

                                   ----------




                              AMENDED AND RESTATED
                          REGISTRATION RIGHTS AGREEMENT

                                   ----------




                                NOVEMBER 30, 2000

<PAGE>   2

                             PENSON WORLDWIDE, INC.
               AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT
                                TABLE OF CONTENTS


<TABLE>
<S>      <C>               <C>                                                                                 <C>
INDEX OF DEFINED TERMS.........................................................................................iii

ARTICLE I REGISTRATION RIGHTS....................................................................................1
         Section 1.1      Certain Definitions....................................................................1
         Section 1.2      Piggyback Registrations................................................................2
         Section 1.3      Demand Registrations...................................................................3
         Section 1.4      Registrations on Form S-3..............................................................4
         Section 1.5      Registration Procedures................................................................4
         Section 1.6      Expenses of Registration...............................................................5
         Section 1.7      Underwritten Registrations.............................................................5
         Section 1.8      Rule 144 Requirements; Termination of Registration Rights..............................5
         Section 1.9      Information by Holder..................................................................6
         Section 1.10     Prospectus Delivery Requirement........................................................6
         Section 1.11     Rule 144 Reporting.....................................................................6
         Section 1.12     Other Registration Rights..............................................................7
         Section 1.13     Listing Application....................................................................7
         Section 1.14     Damages; Injunctive Relief.............................................................7
         Section 1.15     Indemnification........................................................................7
         Section 1.16     Assignment of Registration Rights.....................................................10

ARTICLE II MISCELLANEOUS........................................................................................10
         Section 2.1      Successors and Assigns................................................................10
         Section 2.2      Governing Law.........................................................................10
         Section 2.3      Counterparts..........................................................................10
         Section 2.4      Titles and Subtitles..................................................................10
         Section 2.5      Notices...............................................................................10
         Section 2.6      Expenses..............................................................................11
         Section 2.7      Amendments and Waivers................................................................11
         Section 2.8      Severability..........................................................................11
         Section 2.9      Aggregation of Stock..................................................................12
         Section 2.10     Entire Agreement; No Waiver...........................................................12

Schedule A        Investors
</TABLE>


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<PAGE>   3

                             PENSON WORLDWIDE, INC.
                              AMENDED AND RESTATED
                          REGISTRATION RIGHTS AGREEMENT



                  THIS AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT (the
"Agreement") is made as of the 30th day of November , 2000, by and among Roger
J. Engemoen, Jr., Daniel P. Son, Philip A. Pendergraft (each, an "Investor" and,
collectively, the "Investors") and Penson Worldwide, Inc., a Delaware
corporation (the "Company").

                                    RECITALS:

                  WHEREAS, during the course of their association with the
Company, each of the Investors have contributed significantly, and will continue
to contribute in the future, to the success and growth of the Company.

                  WHEREAS, on September 14, 2000, the Investors and the Company
entered into a Registration Rights Agreement (the "Original Agreement") which
provides the Investors with the right to register shares of Common Stock of the
Company owned by the Investors as of the date thereof.

                  WHEREAS, the Investors and the Company desire to amend and
restate the Original Agreement to include shares of Common Stock purchased by
certain of the Investors since the date of the Original Agreement.

                  NOW, THEREFORE, in consideration of the mutual promises and
covenants set forth herein and for certain other good and valuable
consideration, the receipt and sufficiency of which in hereby acknowledged, the
parties hereto agree as follows:

                                   ARTICLE I

                               REGISTRATION RIGHTS

         SECTION 1. 1 CERTAIN DEFINITIONS. As used in this Agreement, the
following terms shall have the respective meanings set forth below:

                  (a) "Exchange Act" means the Securities Exchange Act of 1934,
as amended, and the rules and regulations promulgated thereunder;

                  (b) "Holder" means the person who is then the record owner of
Registrable Securities which have not been sold to the public.

                  (c) "Registrable Securities" means (i) the Common Stock owned
by the Investors as set forth in Schedule A hereto and (ii) any Common Stock
issued or issuable with respect to the shares referred to in clause (i) by way
of a stock dividend or stock split or in connection with a combination of
shares, recapitalization, merger, consolidation or other


<PAGE>   4

reorganization; provided that any such share shall cease to be a Registrable
Security when sold pursuant to a registration statement declared effective under
the Securities Act or sold to the public pursuant to a broker transaction under
Rule 144 promulgated thereunder.

                  (d) "Registration Expenses" means all expenses incurred by the
Company in compliance with Sections 1.2, 1.3, and 1.4 hereof, including, without
limitation, all registration and filing fees, printing expenses, fees and
disbursements of counsel for the Company, blue sky fees and expenses, the
expense of any special audits incident to or required by any such registration
and the reasonable fees and disbursements of a single special counsel for the
Holders, provided the Holders shall have used their reasonable best efforts to
utilize the counsel for the Company or the Underwriters and shall employ such
separate special counsel only if necessary.

                  (e) "SEC" means the United States Securities and Exchange
Commission.

                  (f) "Securities Act" means the Securities Act of 1933, as
amended, and the rules and regulations promulgated thereunder.

                  (g) "Selling Expenses" means all underwriting discounts,
selling commissions and transfer taxes applicable to the sale of securities by
the Holder, in an offering pursuant to this Agreement.

         SECTION 1.2 PIGGYBACK REGISTRATIONS.

                  (a) If the Company shall determine to register any of its
securities under the Securities Act, either for its own account or the account
of a security holder or holders exercising their registration rights, other than
pursuant to (1) Section 1.3 below; (2) a registration statement relating solely
to employee benefit, stock option or purchase plans, or a transaction pursuant
to Rule 145 promulgated under the Securities Act; or (3) an offering on any
registration form which does not permit secondary sales or does not include
substantially the same information as would be required to be included in a
registration statement covering the sale of Registrable Securities, the Company
will:

                           (i) promptly give to each Holder written notice
thereof (which shall include the number of shares the Company or other security
holder proposes to register and, if known, the name of the proposed
underwriter); and

                           (ii) use its reasonable best efforts to include in
such registration statement all of the Registrable Securities and Common Stock
specified in a written request or requests made by the Holder within twenty (20)
days after receipt of the written notice from the Company described in clause
(i) above. If the underwriter advises the Company that marketing considerations
require a limitation on the number of shares offered pursuant to any
registration statement, the shares sought to be included therein by the Holders
shall be reduced pro rata. In no event shall the amount of securities of the
selling Holders included in the offering be reduced below twenty-five percent
(25%) of the total amount included in such offering, unless such offering is the
initial public offering of the Company's Securities.


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<PAGE>   5

                  (b) If any Investor disapproves of the terms of any Company
underwriting in which his or its shares are to be included under this Section
1.2, he or it may elect to withdraw therefrom by written notice to the Company
and the underwriter delivered at least seven days prior to the effective date of
the registration statement.

         SECTION 1.3 DEMAND REGISTRATIONS.

                  (a) From and after 180 days after the effective date of the
initial public offering of the Company's Common Stock, if the Company receives
in writing a request that the Company effect the registration under the
Securities Act of Registrable Securities, of which at least 10% of the then
outstanding Registrable Securities shall be included in such registration (which
offering must have a per share price of not less than $5.00 per share (as
adjusted for stock dividends, splits, combinations, reclassification and the
like)), the Company will:

                           (i) promptly give written notice of the proposed
registration to all other Holders; and

                           (ii) as soon as practicable, prepare and file and use
its reasonable best efforts to cause to become effective such registration
statement as may be so requested and as would permit or facilitate the sale and
distribution of such portion of the Registrable Securities as is specified in
such request, together with such additional portion of the Registrable
Securities of any Holder(s) joining in such request as may be specified in a
written request given to the Company within thirty (30) days after receipt of
the written notice from the Company specified in clause (i) above.

                  (b) If the underwriter managing the offering advises the
Holders who have requested inclusion of their Registrable Securities in such
registration statement that marketing considerations require a limitation on the
number of shares offered, such limitation shall be imposed pro rata among such
Holders who requested inclusion of Registrable Securities in such registration
statement according to the number of shares of Registrable Securities owned by
each. Neither the Company nor any other shareholder may include shares in such
registration statement without the consent of Holders of a majority of the
Registrable Securities included therein if the underwriter managing such
offering advises the Holders who have included Registrable Securities in such
registration statement that the inclusion of such additional shares may either
limit the number of Registrable Securities which can be sold or adversely affect
the price at which such Registrable Securities can be sold.

                  (c) Notwithstanding Section 1.3(b) above, the Company shall
have the right, exercisable by written notice to the initiating Holders within
thirty (30) days after receipt of their request to effect a registration under
the Securities Act, to include the Company's shares in such registration, in
which event such registration shall be deemed to be a Company-initiated
registration, and the Holders shall have the right to include their Registrable
Securities and shares of Common Stock, as the case may be, therein to the extent
permitted under Section 1.2 above.

                  (d) The Company shall not be obligated to effect more than
three (3) registrations under this Section 1.3. No registration statement
initiated by Holders hereunder


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<PAGE>   6

shall count as a registration under this Section 1.3 unless and until it shall
have been declared effective. Any registration requested under this Section 1.3
which shall not become effective solely by reason of the refusal of the Holders
participating therein to proceed with the registration shall count as a
registration effected under this Section 1.3 unless the Company shall have been
reimbursed for the Registration Expenses incurred by it in connection therewith.

         SECTION 1.4 REGISTRATIONS ON FORM S-3. In addition to the registrations
provided in Sections 1.2 and 1.3 above, in the event the Company is qualified to
file a registration statement on Form S-3 (or similar short form registration)
under the Securities Act, the Company shall give written notice of such fact to
the Holders. Holders of the Registrable Securities may, by written notice to the
Company, require the Company to file a registration statement on Form S-3 to
effectuate registration of such Holders' Registrable Securities. Following the
initial public offering of its securities, the Company will use its reasonable
best efforts to qualify for registration on Form S-3 or any similar short form
registration within the time prescribed by the Securities Act. The Company may
be required to file up to six (6) registrations on Form S-3 upon demand, each
with respect to an aggregate offering of not less than $10,000,000 (as
determined with reference to the number of shares proposed to be sold in such
registration multiplied by the average closing price, or if no closing price is
available, the mean of the bid and asked prices, over the fifteen trading days
preceding the date of such demand), but it shall not be obligated to file more
than one registration statement on Form S-3 in any six month period.

         SECTION 1. 5 REGISTRATION PROCEDURES. In the case of each registration
statement filed by the Company pursuant to this Agreement, the Company will, at
its expense, do the following for the benefit of the Holders:

                  (a) Use its reasonable best efforts to keep such registration
statement effective for a period of 180 days or until the Holders have completed
the distribution described in the registration statement relating thereto, or
such shorter period of time as is specified by Rule 174 promulgated under the
Securities Act, whichever first occurs, and amend or supplement such
registration statement and the prospectus contained therein from time to time to
the extent necessary to comply with the Securities Act and applicable state
securities laws;

                  (b) Use its reasonable best efforts to register or qualify the
securities to be sold by the Holders under such registration under the
applicable securities or "blue sky" laws of such jurisdictions as the
underwriter of such offering shall reasonably deem necessary in order to ensure
a successful offering; provided, that the Company shall not be obligated to
qualify to do business in any jurisdiction where it is not then so qualified or
otherwise required to be so qualified or to take any action which would subject
it to the service of process in suits other than those arising out of such
registration;

                  (c) Furnish such number of prospectuses, including a
preliminary prospectus, in conformity with the requirements of the Securities
Act, and such other documents incident thereto as a Holders from time to time
may reasonably request in order to facilitate the disposition of Registrable
Securities;


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<PAGE>   7

                  (d) In connection with any underwritten offering pursuant to a
registration statement filed pursuant to Section 1.3 hereof, the Company will
enter into an underwriting agreement necessary to effect the offer and sale of
Common Stock, provided such underwriting agreement contains usual and customary
underwriting provisions and is entered into by the Holders and provided further
that if the underwriter so requests, the underwriting agreement will contain
customary contribution provisions on the part of the Company; and

                  (e) Permit each selling shareholder and such shareholder's
counsel or other representatives to inspect and copy such corporate documents as
he may reasonably request, subject to receipt of such written confidentiality
undertaking as the Company may reasonably request.

         SECTION 1.6 EXPENSES OF REGISTRATION. In the event of a registration in
which securities held by Holders are included under this Agreement, the Company
shall pay all Registration Expenses, but shall not be required to pay or
otherwise assume responsibility for Selling Expenses, which shall be the sole
responsibility of the selling Holders.

         SECTION 1.7 UNDERWRITTEN REGISTRATIONS.

                  (a) The Company shall have the right to select the managing
underwriter or underwriters for any underwritten offering made pursuant to a
registration under Section 1.2 or Section 1.4 hereof. The Company also shall
have the right to select the managing underwriter or underwriters in any
registration under Section 1.3 hereof, provided that such managing underwriter
or underwriters shall be reasonably acceptable to the Holders owning a majority
of Registrable Securities included in such registration.

                  (b) In connection with the initial public offering by the
Company, the Holders shall, if requested by the managing underwriter or
underwriters thereof, agree not to sell any of their Registrable Securities or
any other securities of the Company owned by such shareholders in any
transaction other than pursuant to such underwritten offering for a period
beginning 60 days prior to the date the Company and the underwriter reasonably
expect the registration statement to become effective, and for such period not
to exceed 180 days as determined in the discretion of the Board of Directors of
the Company (such agreement shall be pursuant to the standard form of lock-up
agreement of the managing underwriter or underwriters of such initial public
offering).

                  (c) The Company may delay for a maximum of six months any
underwritten offering pursuant to Section 1.2 or Section 1.3 when, in the good
faith judgment of the Board of Directors, (i) a condition or pending transaction
exists, the disclosure of which would reasonably be expected to have a material
adverse effect on the Company, or (ii) a delay in such offering would be in the
best interests of the Company.

         SECTION 1.8 RULE 144 REQUIREMENTS; TERMINATION OF REGISTRATION RIGHTS.

                  (a) At any time and from time to time after the close of
business on the earliest of the date that (i) a registration statement filed by
the Company under the Securities Act becomes effective; (ii) the Company
registers a class of securities under Section 12 of the Exchange Act; or (iii)
the Company issues an offering circular meeting the requirements of


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<PAGE>   8

Regulation A under the Act, the Company shall undertake to make publicly
available, and available upon request to the Holders of Registrable Securities,
such information as is necessary to enable Holders to make sales of their stock
pursuant to Rule 144. The Company shall furnish to any such Holder, upon
request, a written statement executed by the Company setting forth the steps it
has taken to comply with the current public information requirements of Rule
144.

                  (b) The rights of a Holder to demand or participate in any
registration effected under this Agreement shall terminate as to such Holder at
such time as such Holder (i) holds less than five percent (5%) of the fully
diluted shares of Common Stock then outstanding and (ii) such Holder is eligible
to dispose of his shares pursuant to Rule 144(k), as in effect at such time.

         SECTION 1.9 INFORMATION BY HOLDER. Each Holder included in any
registration shall furnish to the Company such information regarding such Holder
and the distribution proposed by such Holder as the Company may reasonably
request in writing and as shall be reasonably required in connection with any
registration, qualification or compliance referred to in this Agreement.

         SECTION 1.10 PROSPECTUS DELIVERY REQUIREMENT. In the event that any
Holders propose to distribute any Registrable Securities in a registered
offering which is not underwritten, such Holders severally agree to comply with
the prospectus delivery requirements of the Securities Act with respect to such
distribution and to furnish evidence of such compliance to the extent reasonably
requested by the Company in connection with such distribution.

         SECTION 1.11 RULE 144 REPORTING. With a view to making available the
benefits of certain rules and regulations of the SEC that permit the sale of
restricted securities (as that term is defined in Rule 144 promulgated under the
Securities Act) to the public without registration, the Company agrees to:

                  (a) use its reasonable best efforts to make and keep public
information available as those terms are understood and defined in Rule 144, at
all times from and after ninety days following the effective date of the first
registration under the Securities Act filed by the Company for an offering of
its securities to the general public;

                  (b) use its reasonable best efforts to file with the SEC in a
timely manner all reports and other documents required of the Company under the
Securities Act and the Exchange Act at any time after it has become subject to
such reporting requirements; and

                  (c) so long as the Holders own any shares of Common Stock,
furnish each of the Holders promptly upon its request, (i) a written statement
by the Company as to its compliance with the reporting requirements of Rule 144
(at any time from and after ninety days following the effective date of the
first registration statement filed by the Company for an offering of its
securities to the general public), and of the Securities Act and Exchange Act
(at any time after it has become subject to such reporting requirements); (ii) a
copy of the most recent annual or quarterly report of the Company; and (iii)
such other reports and documents so filed as the Holder may reasonably request
in availing itself of any rule or regulation of the SEC allowing the Holder to
sell any such securities without registration.


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<PAGE>   9

         SECTION 1.12 OTHER REGISTRATION RIGHTS. From and after the date of this
Agreement, the Company shall not enter into any agreement with any holder or
prospective holder of any securities of the Company giving such holder or
prospective holder the right to require the Company to initiate any registration
of any securities of the Company prior to the date on which the Holders may
initiate a registration or to initiate a registration in which the Holders may
not participate in proportion to their stock ownership, provided that this
Section shall not limit the right of the Company to enter into any agreement
with any holder or prospective holder of any securities of the Company giving
such holder or prospective holder the right, upon any registration of any of the
Company's securities, to include, among the securities which the Company is then
registering, securities owned by such holder. Any right given by the Company to
any holder or prospective holder of the Company's securities in connection with
the registration of securities shall be conditioned such that it shall be
consistent with the rights of the Holders as provided in this Agreement.

         SECTION 1.13 LISTING APPLICATION. If shares of any class of stock of
the Company shall be listed on a national securities exchange or qualified for
inclusion on any interdealer quotation system, the Company shall, at its
expense, include in its listing application all of the shares of the listed
class then owned by the Holders.

         SECTION 1.14 DAMAGES; INJUNCTIVE RELIEF. The Company recognizes and
agrees that the Holders of Registrable Securities shall not have an adequate
remedy if the Company fails to comply with the provisions of this Agreement, and
that damages will not be readily ascertainable, and the Company expressly agrees
that in the event of such failure damages shall not be an exclusive remedy and
the Holders, or any of them, may seek specific performance of the Company's
obligations hereunder.

         SECTION 1.15 INDEMNIFICATION.

                  (a) The Company will, and hereby does, agree to indemnify and
hold harmless each Holder whose securities of the Company are included in any
registration statement, each of its officers, directors, agents, employees and
partners, and each person controlling such Holder (within the meaning of the
Securities Act), with respect to which registration, qualification or compliance
has been effected pursuant to this Agreement, and each underwriter, if any, and
each person who controls such Holder or underwriter within the meaning of the
Securities Act, against all claims, losses, damages, and liabilities (joint or
several) or actions in respect thereof arising out of or based on any untrue
statement (or alleged untrue statement) of a material fact contained in any
prospectus, offering circular or other document (including any related
registration statement, including any preliminary prospectus or final prospectus
contained therein, notification or the like, and all amendments and supplements
thereto) incident to any such registration, qualification or compliance, or
based on any omission (or alleged omissions) to state therein a material fact
required to be stated therein or necessary to make the statements therein not
misleading, or any violation by the Company of the Securities Act or the
Exchange Act or the securities laws of any state or any rule or regulation under
the Securities Act or the Exchange Act or the securities laws of any state
applicable to the Company and relating to action or inaction required of the
Company in connection with any such registration, qualification or compliance,
and, subject to compliance with the provisions of paragraph (c) below, will
promptly reimburse each such Holder, each of its officers, directors,


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<PAGE>   10

agents, employees and partners, and each person controlling such Holder, each
such underwriter and each person who controls any such underwriter, for any
legal and any other expenses reasonably incurred in connection with
investigating and defending any such claim, loss, damage, liability or action,
whether or not resulting in any liability, provided that the Company will not be
liable in any such case to the extent that any such claim, loss, damage,
liability or expense arises out of or is based on any untrue statement (or
alleged untrue statement) or omission (or alleged omission) in reliance upon and
in conformity with written information furnished to the Company by such Holder
or underwriter and stated to be expressly for use therein.

                  (b) Each Holder will, if securities held by such Holder are
included in the securities as to which such registration, qualification or
compliance is being effected, indemnify and hold harmless the Company, each of
its directors, officers, employees and agents and each underwriter, if any, of
the Company's securities covered by such a registration statement, each person
who controls the Company or such underwriter within the meaning of the
Securities Act and the rules and regulations thereunder, each other such Holder
and each of their officers, directors, employees, agents and partners, and each
person controlling such Holder, against all claims, losses, damages and
liabilities (or actions in respect thereof) arising out of or based on any
untrue statement (or alleged untrue statement) of a material fact contained in
any such registration statement, prospectus, offering circular or other document
(and all amendments and supplements thereto), or any omission (or alleged
omission) to state therein a material fact required to be stated therein or
necessary to make the statements therein not misleading, or any violation by
such Holder of the Securities Act or the Exchange Act or any rule or regulation
under the Securities Act or the Exchange Act or the securities laws of any state
applicable to such Holder, and will promptly reimburse the Company and such
other Holders' directors, officers, partners, persons, underwriters or control
persons for any legal or other expenses reasonably incurred in connection with
investigating or defending any such claim, loss, damage, liability or action,
whether or not resulting in liability, in each case to the extent, but only to
the extent, that such untrue statement (or alleged untrue statement) or omission
(or alleged omission) is made in such registration statement, prospectus,
offering circular or other document in reliance upon and in conformity with
written information furnished to the Company by such Holder and stated to be
expressly for use therein; provided that in no event shall any indemnity under
this paragraph exceed the net proceeds from the offering received by such Holder
if such Holder (i) is not, individually or through its affiliates or controlling
persons, a director, executive officer or beneficial holder of in excess of 10%
of the outstanding voting stock of the Company and (ii) had no knowledge
regarding the untruth of any statement (or alleged untrue statement), or any
omission (or alleged omission) upon which any indemnity is sought under this
paragraph. It is understood and agreed that the indemnity stated in this
paragraph (b) is a condition precedent to the Company's obligation to include
securities of the Holder in any registration statement; that the Company will be
relying upon this indemnity as an inducement in doing so; that the Company may,
at its option, require an instrument executed by the Holder and expressly
reaffirming this indemnity as a precondition to proceeding with the registration
of any securities under this Agreement; and that even in the absence of such
instrument, the decision of the Holder to proceed with such registration shall
be deemed a reaffirmation of the provision.

                  (c) Each party entitled to indemnification under this Section
1.5 (the "Indemnified Party") shall give notice to the party required to provide
indemnification (the


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<PAGE>   11

"Indemnifying Party") promptly after such Indemnified Party has actual knowledge
of any claim as to which indemnity may be sought, but the failure of any
Indemnified Party to give such notice shall not relieve the Indemnifying Party
of its obligations under this Agreement (except and to the extent the
Indemnifying Party has been prejudiced as a consequence thereof). The
Indemnified Party will be entitled to participate in, and to the extent that it
may elect by written notice delivered to the Indemnifying Party promptly after
receiving the aforesaid notice from such Indemnifying Party, at its expense to
assume, the defense of any such claim or any litigation resulting therefrom,
with counsel reasonably satisfactory to such Indemnified Party; provided that
the Indemnified Party may participate in such defense at its expense,
notwithstanding the assumption of such of defense by the Indemnifying Party, and
provided, further, that if the defendants in any such action shall include both
the Indemnified Party and the Indemnifying Party, and the Indemnified Party
shall have reasonably concluded that there may be legal defenses available to it
and/or other Indemnified Parties which are different from or additional to those
available to the Indemnifying Party, the Indemnified Party or Parties shall have
the right to select separate counsel to assert such legal defenses and to
otherwise participate in the defense of such action on behalf of such
Indemnified Party or Parties and the reasonable fees and expenses of such
counsel shall be paid by the Indemnifying Party unless such different or
additional defenses are determined by a court of competent jurisdiction to be
invalid or such court bases its decision on common defenses, in which cases the
Indemnified Party or Parties shall pay the fees and expenses of such separate
counsel.

                  (d) No Indemnifying Party, in the defense of any such claim or
litigation, shall, except with the consent of each Indemnified Party, consent to
entry of any judgment against or enter into any settlement concerning any
Indemnified Party which does not include as an unconditional term thereof the
giving by the claimant or plaintiff to such Indemnified Party of a release from
all liability in respect of such claim or litigation. Each Indemnified Party
shall provide such reasonable cooperation and shall furnish such information
regarding itself or the claim in question as an Indemnifying Party may
reasonably request in writing and as shall be reasonably required in connection
with defense of such claim and litigation resulting therefrom.

                  (e) If the indemnification provided for in this Section 1.15
is held by a court of competent jurisdiction to be unavailable to an Indemnified
Party with respect to any losses, claims, damages or liabilities referred to
herein, the Indemnifying Party, in lieu of indemnifying such Indemnified Party
thereunder, shall to the extent permitted by applicable law contribute to the
amount paid or payable by such Indemnified Party as a result of such loss,
claim, damage or liability in such proportion as is appropriate to reflect the
relative fault of the Indemnifying Party on the one hand and of the Indemnified
Party on the other in connection with the violation(s) that resulted in such
loss, claim, damage or liability, as well as any other relevant equitable
considerations. The relative fault of the Indemnifying Party and of the
Indemnified Party shall be determined by a court of law by reference to, among
other things, whether the untrue or alleged untrue statement of a material fact
or the omission to state a material fact relates to information supplied by the
Indemnifying Party or by the Indemnified Party and the parties' relative intent,
knowledge, access to information and opportunity to correct or prevent such
statement or omission; provided that in no event shall any contribution under
this paragraph exceed the net proceeds from the offering received by such Holder
if such Holder (i) is not, individually or through its affiliates or controlling
persons, a director, executive officer or beneficial holder of in excess of 10%
of the outstanding voting stock of the Company and (ii)


                                       9
<PAGE>   12

had no knowledge regarding the untruth of any statement (or alleged untrue
statement), or any omission (or alleged omission) upon which any contribution is
sought under this paragraph.

                  (f) Neither the Company nor any Holder shall be required to
participate in a registration pursuant to which it would be required to execute
an underwriting agreement in connection with a registration effected under
Section 1.2 or Section 1.3 which imposes indemnification or contribution
obligations on the Company or such Holder, as the case may be, more onerous than
those imposed hereunder.

         SECTION 1.16 ASSIGNMENT OF REGISTRATION RIGHTS. The rights to cause the
Company to register Registrable Securities pursuant to this Article I may be
assigned by a Holder to a transferee or assignee of Registrable Securities which
(i) is a subsidiary, affiliate, member, parent, general partner, limited
partner, trust grantor or beneficiary, or retired partner of a Holder, (ii) is a
Holder's family member or trust for the benefit of an individual Holder, (iii)
is already a Holder of Registrable Securities or (iv) acquires at least five
hundred (500) shares of Registrable Securities (as adjusted for stock splits and
combinations); provided, such transfer shall be subject to the following: (A)
the transferor shall, within ten (10) days after such transfer, furnish to the
Company written notice of the name and address of such transferee or assignee
and the securities with respect to which such registration rights are being
assigned and (B) such transferee shall agree to be subject to all restrictions
set forth in this Agreement.

                                   ARTICLE II

                                  MISCELLANEOUS

         SECTION 2.1 SUCCESSORS AND ASSIGNS. Except as otherwise provided
herein, the terms and conditions of this Agreement shall inure to the benefit of
and be binding upon the respective successors and assigns of the parties
(including transferees of any shares of Registrable Securities). Nothing in this
Agreement, express or implied, is intended to confer upon any party other than
the parties hereto or their respective successors and assigns any rights,
remedies, obligations, or liabilities under or by reason of this Agreement,
except as expressly provided in this Agreement.

         SECTION 2.2 GOVERNING LAW. This Agreement shall be governed by and
construed under the laws of the State of Texas, without giving effect to
conflicts of laws principles.

         SECTION 2.3 COUNTERPARTS. This Agreement may be executed in two or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

         SECTION 2.4 TITLES AND SUBTITLES. The titles and subtitles used in this
Agreement are used for convenience only and are not to be considered in
construing or interpreting this Agreement.

         SECTION 2.5 NOTICES. All notices and other communications hereunder
shall be in writing and shall be deemed given if delivered personally or by
commercial delivery service, or mailed by registered or certified mail (return
receipt requested) or sent via facsimile (with


                                       10
<PAGE>   13

confirmation of receipt) to the parties at the address for each party set forth
beneath each party's as follows (or at such other address for a party as shall
be specified by like notice):

                        (i)   if to the Company:

                                    Penson Worldwide, Inc.
                                    1700 Pacific Avenue, Suite 1400
                                    Dallas, Texas 75201
                                    Attn:  General Counsel
                                    Fax:  (214) 765-1264

                        with a copy to:

                                    Brobeck, Phleger & Harrison LLP
                                    301 Congress Avenue, Suite 1200
                                    Austin, Texas 78701
                                    Attn: Thomas P. Mason
                                    Fax: (512) 477-5813

                        (ii)  if to the Investors:

                              At the addresses set forth on Schedule A hereto.

                  Notice given by personal delivery, courier service or mail
shall be effective upon actual receipt. Notice given by telecopier shall be
confirmed by appropriate answer back and shall be effective upon actual receipt
if received during the recipient's normal business hours, or at the beginning of
the recipient's next business day after receipt if not received during the
recipient's normal business hours. Any party may change any address to which
notice is to be given to it by giving notice as provided above of such change of
address.

         SECTION 2.6 EXPENSES. If any action at law or in equity is necessary to
enforce or interpret the terms of this Agreement, the prevailing party shall be
entitled to reasonable attorneys' fees, costs and necessary disbursements in
addition to any other relief to which such party may be entitled.

         SECTION 2.7 AMENDMENTS AND WAIVERS. Any term of this Agreement may be
amended and the observance of any term of this Agreement may be waived (either
generally or in a particular instance and either retroactively or
prospectively), only with the written consent of the Company and the holders of
at least a majority of the Registrable Securities then outstanding. Any
amendment or waiver effected in accordance with this Section shall be binding
upon each Holder of any Registrable Securities then outstanding, each future
holder of all such Registrable Securities and the Company.

         SECTION 2.8 SEVERABILITY. If one or more provisions of this Agreement
are held to be unenforceable under applicable law, such provision shall be
excluded from this Agreement and the balance of the Agreement shall be
interpreted as if such provision were so excluded and shall be enforceable in
accordance with its terms.


                                       11
<PAGE>   14

         SECTION 2.9 AGGREGATION OF STOCK. All shares of Registrable Securities
held or acquired by affiliated entities or persons shall be aggregated together
for the purpose of determining the availability of any rights under this
Agreement.

         SECTION 2.10 ENTIRE AGREEMENT; NO WAIVER. This Agreement (including the
Exhibits hereto, if any) constitutes the full and entire understanding and
agreement between the parties with regard to the subjects hereof and thereof and
does hereby supersede the Previous Agreement. No course of dealing between or
among the parties hereto or any delay in exercising any rights hereunder shall
operate as a waiver of any rights of any such party.


         [THE REMAINDER OF THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.]



                                       12
<PAGE>   15


                  IN WITNESS WHEREOF, the parties have executed this Amended and
Restated Registration Rights Agreement as of the date first above written.



                                    COMPANY:

                                    PENSON WORLDWIDE, INC.


                                    By: /s/ ROGER J. ENGEMOEN, JR.
                                       -----------------------------------------
                                         Roger J. Engemoen, Jr.,  Chairman



                                    INVESTORS:

                                     /s/ ROGER J. ENGEMOEN, JR.
                                    --------------------------------------------
                                    Roger J. Engemoen, Jr.

                                     /s/ DANIEL P. SON
                                    --------------------------------------------
                                    Daniel P. Son

                                     /s/ PHILIP A. PENDERGRAFT
                                    --------------------------------------------
                                    Philip A. Pendergraft


                    [SIGNATURE PAGE TO AMENDED AND RESTATED
                         REGISTRATION RIGHTS AGREEMENT]

<PAGE>   16

                                   Schedule A

                                    Investors


<TABLE>
<CAPTION>
                         NAMES                                                  SHARES
                         -----                                                  ------
<S>                                                                            <C>
                         Roger J. Engemoen, Jr.                                7,518,150
                         1501 Barclay Drive
                         Austin, Texas 78746

                         Daniel P. Son                                         2,362,500
                         7138 Azalea Lane
                         Dallas, Texas 75230

                         Philip A. Pendergraft                                 2,362,500
                         2708 Big Bear Lake Drive
                         Arlington, Texas 76016
</TABLE>