SECURITIES AND EXCHANGE COMMISSION
                              Washington D.C. 20549


                                  SCHEDULE 13G
                    Under the Securities Exchange Act of 1934

                           (Amendment Number Sixteen)



                               Redwood Trust, Inc.
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                                (Name of Issuer)

                                     Common
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                         (Title of Class of Securities)

                                    758075402
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                                 (Cusip Number)

                                   12/31/2007
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             (Date of Event Which Requires Filing of this Statement)



Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

     [X] Rule 13d-1 (b)

     [ ] Rule 13d-1 (c)

     [ ] Rule 13d-1 (d)


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CUSIP NO. 758075402                                                          13G


1)   NAME OF REPORTING PERSON                  I.R.S. NUMBER OF REPORTING PERSON
     Wallace R. Weitz & Company                Tax I.D. No. 47-0654095

2)   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:
        (a) [ ]
        (b) [X]

3)   SEC USE ONLY

4)   CITIZENSHIP OR PLACE OF ORGANIZATION State of Nebraska

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:
5)   Sole Voting Power:                     5,887,862*
6)   Shared Voting Power:                   5,887,862*
7)   Sole Dispositive Power:                5,945,362
8)   Shared Dispositive Power:              None

9)   AGGREGATE AMOUNT OWNED BY EACH REPORTING PERSON
        5,945,362

10)  CHECK IF THE AGGREGATE AMOUNT IN ROW 9 EXCLUDES CERTAIN SHARES
        [ ]

11)  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9.
        18.5%

12)  TYPE OF REPORTING PERSON
        IA

*2,790,660 of the shares of common stock are subject to a Voting Agreement
pursuant to which Wallace R. Weitz & Company has transferred its voting rights
with respect to such shares to certain principal shareholders of Redwood Trust.


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CUSIP NO. 758075402                                                          13G

1)       NAME OF REPORTING PERSON Wallace R. Weitz

2)       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP: (a) [ ] N/A
(b)      [      ]

3)       SEC USE ONLY

4)       CITIZENSHIP OR PLACE OF ORGANIZATION Citizen of the United States of
         America

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:
5)   Sole Voting Power:                     None
6)   Shared Voting Power:                   5,887,862*
7)   Sole Dispositive Power:                None
8)   Shared Dispositive Power:              5,945,362

9)   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
        5,945,362

10)  CHECK IF THE AGGREGATE AMOUNT IN ROW 9 EXCLUDES CERTAIN SHARES
        [ ]

11)  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
        18.5%

12)  TYPE OF REPORTING PERSON
        IN

*2,790,660 of the shares of common stock are subject to a Voting Agreement
pursuant to which Wallace R. Weitz & Company has transferred its voting rights
with respect to such shares to certain principal shareholders of Redwood Trust.


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Item 1(a).  Name of Issuer:
                  Redwood Trust, Inc.

Item 1(b).  Address of Issuer's Principal Executive Office:
                  One Belvedere Place, # 300
                  Mill Valley, California  94941

Item 2(a).  Names of Persons Filing:
                  Wallace R. Weitz & Company
                  Wallace R. Weitz, President and Primary Owner of Wallace R.
                    Weitz & Company

Item 2(b).  Principal Business Address of Persons Filing:
                  1125 South 103rd Street, Suite 600
                  Omaha, Nebraska 68124-6008

Item 2(c).  Citizenship:
                  Wallace R. Weitz & Company - State of Nebraska
                  Wallace R. Weitz - Citizen of United States of America

Item 2(d).  Title of Class of Securities:
                  Common Stock

Item 2(e).  CUSIP Number:
                  758075402

Item 3.   If this statement is filed pursuant to Rules 13d-1(b), or 13d-2(b),
check whether the person filing is a:

     (e)  Investment Adviser registered under Section 203 of the Investment
          Advisers Act of 1940. This statement is being filed by Wallace R.
          Weitz & Company ("Weitz & Co.") as a registered investment adviser.
          All of the securities reported in this statement are owned of record
          by investment advisory clients of Weitz & Co. and none are owned
          directly or indirectly by Weitz & Co. As permitted by Rule 13d-4, the
          filing of this statement shall not be construed as an admission that
          Weitz & Co. is the beneficial owner of any of the securities covered
          by the statement.

     (g)  Control Person. This statement is also being filed by Wallace R. Weitz
          ("Weitz"), President and primary owner of Weitz & Co. in the event he
          could be deemed to be an indirect beneficial owner of the securities
          reported by Weitz & Co. through the exercise of voting control and/or
          dispositive power over the securities as a result of his official
          positions or ownership of the voting securities of Weitz & Co. Mr.
          Weitz does not own directly or indirectly any securities covered by
          this statement for his own account. As permitted by Rule 13d-4, the
          filing of this statement shall not be construed as an admission that
          Mr. Weitz is the beneficial owner of any of the securities covered by
          this statement.

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Item 4.  Ownership:

     (a)  Amount Beneficially Owned:

          (i)  Weitz & Co. 5,945,362 Shares

          (ii) Weitz       5,945,362 Shares

     (b)  Percent of Class:

          (i)  Weitz & Co. 18.5%

          (ii) Weitz       18.5%

     (c)  Number of Shares as to which such person has:

          (i)  sole power to direct vote:

               (i)  Weitz & Co. 5,887,862*

               (ii) Weitz       0

          (ii) shared power to direct vote:

               (i)  Weitz & Co. 5,887,862*

               (ii) Weitz       5,887,862*

         (iii) sole power to dispose:

               (i)  Weitz & Co. 5,945,362

               (ii) Weitz       0

          (iv) shared power to dispose:

               (i)  Weitz & Co. 5,945,362

               (ii) Weitz       5,945,362

Item 5.  Ownership of Five Percent or Less of a Class
                  N/A

Item 6.  Ownership of  More Than Five Percent on Behalf of Another Person
                  The Weitz Funds-Value Fund, a registered investment company,
                  is the record owner of 2,455,000** shares of the Issuer as of
                  December 31, 2007, representing 7.6% of the Issuer's shares.
                  The Weitz Funds - Partners Value Fund, a registered investment
                  company, is the record owner of 2,045,515** of the Issuer's
                  shares as of December 31, 2007, representing 6.4% of the
                  Issuer's shares. Weitz & Co. has the sole power to vote or
                  direct the vote of the securities owned by the Value Fund and
                  the Partners Value Fund.

*2,790,660 of the shares of common stock are subject to a Voting Agreement
pursuant to which Wallace R. Weitz & Company has transferred its voting rights
with respect to such shares to certain principal shareholders of Redwood Trust.

**1,152,339 of the shares owned by the Value Fund and 960,133 of the shares
owned by the Partners Value Fund are subject to a Voting Agreement pursuant to
which Wallace R. Weitz & Company has transferred its voting rights with respect
to such shares to certain principal shareholders of Redwood Trust, Inc.


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7 Item 7. Identification and Classification of the Subsidiary Which Acquired the
Security Being Reported on By the Parent Holding Company
                  N/A

Item 8.  Identification and Classification of Members of the Group
                  N/A

Item 9.  Notice of Dissolution of Group
                  N/A

Item 10.  Certification
         By signing below I certify that, to the best of my knowledge and
         belief, the securities referred to above were acquired in the ordinary
         course of business and were not acquired for the purpose of and do not
         have the effect of changing or influencing the control of the issuer of
         such securities and were not acquired in connection with or as a
         participant in any transaction having such purposes or effect.

         After reasonable inquiry and to the best of my knowledge and belief, I
         certify that the information set forth in this statement is true,
         complete and correct.

         Date:    January 11, 2008

         WALLACE R. WEITZ & COMPANY

         By:      /s/ Wallace R. Weitz
         Name:    Wallace R. Weitz
         Title:   President

         WALLACE R. WEITZ
         (Individually)

         /s/ Wallace R. Weitz

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                             Joint Filing Agreement

In accordance with Rule 13d-1 (k) under the Securities Exchange Act of 1934, the
persons or entities named below agree to the joint filing on behalf of each of
them of this Schedule 13G with respect to the securities of the Issuer and
further agree that this joint filing agreement be included as an exhibit to this
Schedule 13G. In evidence thereof, the undersigned hereby execute this agreement
as of the 11th day of January, 2008.

         WALLACE R. WEITZ & COMPANY

         By:      /s/ Wallace R. Weitz
         Name:    Wallace R. Weitz
         Title:   President

         WALLACE R. WEITZ
         (Individually)

         /s/ Wallace R. Weitz


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