THIS FILING LISTS SECURITIES HOLDINGS REPORTED ON THE FORM 13F FILED ON
FEBRUARY 11, 2010 PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT AND FOR
WHICH THAT REQUEST FOR CONFIDENTIAL TREATMENT HAS EXPIRED

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

                                  FORM 13F

                            FORM 13F COVER PAGE


Report for the Calendar Quarter ended:  03/31/2010

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. (1)
Address:  2101 Cedar Springs Road, 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            May 13, 2011
    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:  2

Form 13F Information Table Value Total:  $154,791 (thousands)

List of Other Included Managers:  NONE

(1)  HBK Investments L.P. has delegated discretion to vote and dispose of the
     securities described below to HBK Services LLC ("Services").  Services
     may, from time to time, delegate discretion to vote and dispose of
     certain of such Securities to one or more subadvisors.  Each of Services
     and such subadvisors is under common control with HBK Investments L.P.
     The filing of this report shall not be deemed an admission that such
     subadvisors are, for the purpose of Section 13(d) or 13(g) of the
     Securities Exchange Act of 1934, beneficial owners of such securities.







CONFIDENTIAL 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
                                                                               

VARIAN INC                     COM              922206107       49191    950007  SHR         SOLE            950007    0     0
MILLIPORE CORP                 COM              601073109      105600   1000000  SHR         SOLE           1000000    0     0