13F-HR/A 1 c17343e13fvhrza.txt 13F HOLDINGS REPORT AMENDMENT UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 13F Form 13F COVER PAGE Report for the Calendar Year or Quarter Ended: December 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: Magnetar Financial LLC Address: 1603 Orrington Avenue, 13th Floor Evanston, IL 60201 Form 13F File Number: 28-11800 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 Reporting Manager: Name: Michael Turro Title: Chief Compliance Officer Phone: 847-905-4690 Signature, Place, and Date of Signing: /s/ Michael Turro Evanston, IL May 16, 2011 ------------------------------------- ------------- ------------ [Signature] [City, State] [Date] Report Type (Check only one.): [X] 13F HOLDINGS REPORT. (Check here if all holdings of this reporting manager are reported in this report.) [ ] 13F NOTICE. (Check here if no holdings reported are in this report, and all holdings are reported by other reporting manager(s).) [ ] 13F COMBINATION REPORT. (Check here if a portion of the holdings for this reporting manager are reported in this report and a portion are reported by other reporting manager(s).) FORM 13F SUMMARY PAGE Report Summary: Number of Other Included Managers: 0 Form 13F Information Table Entry Total: 11 Form 13F Information Table Value Total: $354,445 (thousands) List of Other Included Managers: NONE FORM 13F INFORMATION TABLE
COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8 ---------------------------- -------- --------- -------- ------------------ ---------- -------- --------------------- VOTING AUTHORITY NAME OF TITLE OF VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER --------------------- ISSUER CLASS CUSIP [x$1000] PRN AMT PRN CALL DISCRETION MANAGERS SOLE SHARED NONE ---------------------------- -------- --------- -------- --------- --- ---- ---------- -------- --------- ------ ---- * AIRGAS INC COM 009363102 27,232 436,000 SH SOLE 436,000 * AIRGAS INC COM 009363102 12,492 200,000 SH CALL SOLE 200,000 *ALCON INC COM SHS H01301102 42,680 261,201 SH SOLE 261,201 *BUCYRUS INTL INC COM 118759109 11,093 124,082 SH SOLE 124,082 *COMPELLENT TECHNOLOGIES INC COM 20452A108 11,535 418,100 SH SOLE 418,100 * GENZYME CORP COM 372917104 44,656 627,190 SH SOLE 627,190 * GENZYME CORP COM 372917104 100,712 1,414,500 SH CALL SOLE 1,414,500 * GENZYME CORP COM 372917104 44,642 627,000 SH PUT SOLE 627,000 *SONIC SOLUTIONS COM 835460106 14,512 967,456 SH SOLE 967,456 *TENET HEALTHCARE CORP COM 88033G100 28,923 4,323,271 SH SOLE 4,323,271 *TENET HEALTHCARE CORP COM 88033G100 15,908 2,377,900 SH PUT SOLE 2,377,900