THIS FILING LISTS SECURITIES HOLDINGS REPORTED ON THE FORM 13F FILED ON
FEBRUARY 14, 2006 PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT AND
FOR WHICH CONFIDENTIAL TREATMENT EXPIRED.

                               UNITED STATES
                     SECURITIES AND EXCHANGE COMMISSION
                           Washington, D.C. 20549

                                  FORM 13F

                            FORM 13F COVER PAGE


Report for the Calendar Quarter ended:  12/31/05

Check here if Amendment [X]; Amendment Number: 1
     This Amendment (check only one.):  [ ] is a restatement.
                                        [X] adds new holdings entries.

Institutional Investment Manager Filing this Report:

Name:     HBK Investments L.P.
Address:  300 Crescent Court, Suite 700
          Dallas, Texas 75201

Form 13F File Number: 28-6078

The institutional investment manager filing this report and the person by
whom it is signed hereby represent that the person signing the report is
authorized to submit it, that all information contained herein is true,
correct and complete, and that it is understood that all required items,
statements, schedules, lists, and tables, are considered integral parts of
this form.

Person Signing this Report on Behalf of Report Manager:

Name:     Jon L. Mosle
Title:    General Counsel
Phone:    (214) 758-6107

Signature, Place, and Date of Signing:

/X/ Jon L. Mosle          Dallas, Texas       February 9, 2007
    General Counsel

Report Type (Check only one.):

[X]  13F HOLDINGS REPORT.

[ ]  13F NOTICE.

[ ]  13F COMBINATION REPORT.

I AM SIGNING THIS REPORT AS REQUIRED BY THE SECURITIES EXCHANGE ACT OF
1934.




FORM 13F SUMMARY PAGE


Report Summary:

Number of Other Included Managers:       0

Form 13F Information Table Entry Total:  3

Form 13F Information Table Value Total:  $597,796 (thousands)

List of Other Included Managers:  NONE






FORM 13F INFORMATION TABLE

                                TITLE OF                         VALUE     SHARES/  SH/  PUT/ INVSTMNT  OTHR    VOTING AUTHORITY
NAME OF ISSUER                   CLASS               CUSIP      (X$1000)   PRN AMT  PRN  CLL  DISCRETN  MGRS    SOLE   SHRD  NONE
                                                                               

GUIDANT CORP                    COM                401698105     340345   5256300  SHR         SOLE           5256300    0     0
GUIDANT CORP                    COM                401698105     240177   3709300  SHR  PUT    SOLE           3709300    0     0
MAXTOR CORP                     COM NEW            577729205      17274   2489100  SHR         SOLE           2489100    0     0