EXHIBIT 4.2

AMENDMENT TO THE REGISTRATION RIGHTS AGREEMENT

This Amendment to the
Registration Rights Agreement (the Amendment) is entered into
as of August 16, 2001, by and among OptiMark Holdings, Inc., a Delaware
corporation (the Company), and each of the entities whose
names are set forth on the signature pages hereto.

WHEREAS,
the Company and the holders (which holders are hereinafter collectively referred
to as Initial Holders) of the Companys Series E
Cumulative Preferred Stock, par value $0.01 per share (the Series E
Shares), whose names are set forth on the Schedule of Initial Holders
attached as Annex A to this Amendment have entered into a Registration
Rights Agreement, dated as of June 29, 2001 (the Registration
Rights Agreement). Defined terms used herein but not defined herein
shall have the meanings ascribed to them in the Registration Rights Agreement;
and

WHEREAS, the Company has
requested that the Initial Holders agree to amend the Registration Rights
Agreement and the Initial Holders, being the Holders of more than 50 percent of
the Registrable Securities outstanding as of the date hereof, have agreed to
accommodate such request.

NOW,
THEREFORE, for good and valuable consideration, the receipt and sufficiency of
which are hereby acknowledged, the parties, intending to be legally bound,
hereby agree as follows:

1.     Amendment of Schedule
I.  Schedule I of the Registration Rights Agreement is hereby
deleted and replaced in its entirety by the following:

### Schedule I

|Closing Date | Purchaser | Purchase Price |  | PreferredShares
Issued
|------------ | --------- | -------------- |  | ----------------------

|June 29, 2001      | Softbank Capital Partners LP      | $3,024,879  |  | 201,658
|------------------ | --------------------------------- | ----------- |  | -------
|                   | Softbank Capital LP               | $2,972,910  |  | 198,194
|                   | Softbank Capital Advisors Fund LP | $52,211     |  | 3,480  
|                   |                                   |             |  |        
|                   |                                   | $6,050,000  |  | 403,332
|July 13, 2001      | Softbank Capital Partners LP      | $549,978    |  | 36,665 
|                   | Softbank Capital LP               | $540,529    |  | 36,035 
|                   | Softbank Capital Advisors Fund LP | $9,493      |  | 633    
|                   |                                   |             |  |        
|                   |                                   | $1,100,000  |  | 73,333 
|                   |                                   |             |  |        
|August 13, 2001    | Softbank Capital Partners LP      | $651,759.65 |  | 43,451 
|                   | Softbank Capital LP               | $640,561.96 |  | 42,704 
|                   | Softbank Capital Advisors Fund LP | $11,249.82  |  | 750    
|                   | Big Island LLC                    | $21,428.57  |  | 1,428  
|                   |                                   |             |  |        
|                   |                                   | $1,325,000  |  | 88,333 
|                   |                                   |             |  |        
|September 14, 2001 | Softbank Capital Partners LP      | $680,758.49 |  | 45,384 
|                   | Softbank Capital LP               | $669,062.58 |  | 44,604 

|                         | Softbank Capital Advisors Fund LP | $11,750.36  |  | 784      
|------------------------ | --------------------------------- | ----------- |  | ---------
|                         | Big Island LLC                    | $21,428.57  |  | 1,428    
|                         |                                   |             |  |          
|                         |                                   | $1,383,000  |  | 92,200   
|                         |                                   |             |  |          
|October 11, 2001         | Softbank Capital Partners LP      | $614,261.15 |  | 40,951   
|                         | Softbank Capital LP               | $603,707.71 |  | 40,247   
|                         | Softbank Capital Advisors Fund LP | $10,602.57  |  | 707      
|                         | Big Island LLC                    | $21,428.57  |  | 1,428    
|                         |                                   |             |  |          
|                         |                                   | $1,250,000  |  | 83,333   
|                         |                                   |             |  |          
|November 13, 2001        | Softbank Capital Partners LP      | $539,264.15 |  | 35,951   
|                         | Softbank Capital LP               | $529,999.21 |  | 35,333   
|                         | Softbank Capital Advisors Fund LP | $9,308.07   |  | 621      
|                         | Big Island LLC                    | $21,428.57  |  | 1,428    
|                         |                                   |             |  |          
|                         |                                   | $1,100,000  |  | 73,333   
|                         |                                   |             |  |          
|December 13, 2001        | Softbank Capital Partners LP      | $539,264.15 |  | 35,951   
|                         | Softbank Capital LP               | $529,999.21 |  | 35,333   
|                         | Softbank Capital Advisors Fund LP | $9,308.07   |  | 621      
|                         | Big Island LLC                    | $21,428.57  |  | 1,428    
|                         |                                   |             |  |          
|                         |                                   | $1,100,000  |  | 73,333   
|                         |                                   |             |  |          
|January 14, 2002         | Softbank Capital Partners LP      | $539,264.15 |  | 35,951   
|                         | Softbank Capital LP               | $529,999.21 |  | 35,333   
|                         | Softbank Capital Advisors Fund LP | $9,308.07   |  | 621      
|                         | Big Island LLC                    | $21,428.57  |  | 1,428    
|                         |                                   |             |  |          
|                         |                                   | $1,100,000  |  | 73,333   
|                         |                                   |             |  |          
|February 13, 2002        | Softbank Capital Partners LP      | $285,274.31 |  | 19,018   
|                         | Softbank Capital LP               | $280,373.09 |  | 18,693   
|                         | Softbank Capital Advisors Fund LP | $4,924.03   |  | 327      
|                         | Big Island LLC                    | $21,428.57  |  | 1,432    
|                         |                                   |             |  |          
|                         |                                   | $592,000    |  | 39,470   
|                         |                                   |             |  |          
|                         |                                   |             |  |          
|                         |                                   |             |  |          
|Total After All Closings |                                   | $15,000,000 |  | 1,000,000

2.     No Other Amendments;
Registration Rights Agreement Remains in Effect.  Except as expressly amended
by this Amendment, the Registration Rights Agreement shall remain in full force
and effect in the form in which it existed immediately prior to the execution
and delivery of this Amendment.

3.     Fees and Expenses.  Each party shall
bear its own fees and expenses incurred in connection with the
negotiation, preparation, execution and delivery of this Amendment.

4.     Modification and
Waiver.  No amendment or modification of the terms or provisions of this
Amendment shall be binding unless the same shall be in writing and duly executed
by the parties hereto. No waiver of any of the provisions of this Amendment
shall be deemed to or shall constitute a waiver of any other provisions hereof.
No delay on the part of any party in exercising any right, power or privilege
hereunder shall operate as a waiver thereof.

2

5.     No
Implied Rights.  Nothing herein, express or implied, is intended to or shall
be construed to confer upon or give to any person, firm, corporation or legal
entity, other than the parties hereto and their affiliates, any interest,
rights, remedies or other benefits with respect to or in connection with any
agreement or provision contained herein or contemplated hereby.

6.     Entire Agreement.  
This Amendment and the Registration Rights Agreement set forth the entire
understanding of the parties with respect to the subject matter hereof and
thereof. Any previous understandings between the parties regarding the subject
matter hereof and thereof are merged into and superseded by this Amendment and
the Registration Rights Agreement.

7.     Counterparts.  This Amendment
may be executed in one or more counterparts, each of which shall be deemed to be
an original, but all of which shall constitute one and the same instrument.

8.     Governing Law.  This Amendment
shall be governed by and construed in accordance with the laws of the State of
New York.

3

IN
WITNESS WHEREOF, the parties hereto have executed this Amendment to the
Registration Rights Agreement as of the date set forth in the first paragraph
hereof.

| | OPTIMARK HOLDINGS, INC.
| | -----------------------

| | By: | /s/ Robert J Warshaw              | 
| | --- | --------------------------------- | 
| |     |                                   | 
| |     | Name: Robert J Warshaw
Title: CEO | 

| | SOFTBANK CAPITAL PARTNERS LP
| | ----------------------------

| | By: | SOFTBANK Capital Partners LLCIts General Partner | 
| | --- | ------------------------------------------------ | 

| | By: | /s/ Steven J. Murray                        | 
| | --- | ------------------------------------------- | 
| |     |                                             | 
| |     | Name: Steven J. Murray
Title: Admin. Member | 

| | Address:1188 Centre Street
Newton Center, Massachusetts  02459
Attention:  Ron Fisher
Facsimile No.:  (617) 928-9301
| | --------------------------------------------------------------------------------------------------------------------

4

| | SOFTBANK CAPITAL LP
| | -------------------

| | By: | SOFTBANK Capital Partners LLCIts General Partner | 
| | --- | ------------------------------------------------ | 

| | By: | /s/ Steven J. Murray                        | 
| | --- | ------------------------------------------- | 
| |     |                                             | 
| |     | Name: Steven J. Murray
Title: Admin. Member | 

| | Address:1188 Centre Street
Newton Center, Massachusetts  02459
Attention:  Ron Fisher
Facsimile No.:  (617) 928-9301
| | --------------------------------------------------------------------------------------------------------------------

| | SOFTBANK CAPITAL ADVISORS FUND LP
| | ---------------------------------

| | By: | SOFTBANK Capital Partners LLCIts General Partner | 
| | --- | ------------------------------------------------ | 

| | By: | /s/ Steven J. Murray                        | 
| | --- | ------------------------------------------- | 
| |     |                                             | 
| |     | Name: Steven J. Murray
Title: Admin. Member | 

| | Address:1188 Centre Street
Newton Center, Massachusetts  02459
Attention:  Ron Fisher
Facsimile No.:  (617) 928-9301
| | --------------------------------------------------------------------------------------------------------------------

Acknowledged and AgreedBIG ISLAND LLC

|By: |                                      | 
|--- | ------------------------------------ | 
|    |                                      | 
|By: | /s/ David R. Duncan                  | 
|    |                                      | 
|    | Name: David R. Duncan
Title: Manager | 

|Address:1777 South Harrison Street
Penthouse One
Denver, Colorado  80210
Attention:  David R. Duncan
Facsimile No.:  (303) 757-0252 | 
|----------------------------------------------------------------------------------------------------------------------------------- | 

5

Annex A

##### Schedule of Initial Holders

Softbank Capital Partners LP
Softbank Capital LP
Softbank Capital Advisors Fund LP