SEC Form 3
FORM 3 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
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1. Name and Address of Reporting Person*
Magnetar Financial LLC

(Last) (First) (Middle)
1603 ORRINGTON AVE.
13TH FLOOR

(Street)
EVANSTON IL 60201

(City) (State) (Zip)
2. Date of Event Requiring Statement (Month/Day/Year)
06/20/2006
3. Issuer Name and Ticker or Trading Symbol
Opexa Therapeutics, Inc. [ OPXA ]
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director X 10% Owner
Officer (give title below) Other (specify below)
5. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
Form filed by One Reporting Person
X Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock 672,185 I See Footnote(1)
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4) 2. Date Exercisable and Expiration Date (Month/Day/Year) 3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 6. Nature of Indirect Beneficial Ownership (Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Common Stock Warrants (right to buy) (2) 04/11/2011 Common Stock 32,000 6.5(3) I See Footnote(4)
1. Name and Address of Reporting Person*
Magnetar Financial LLC

(Last) (First) (Middle)
1603 ORRINGTON AVE.
13TH FLOOR

(Street)
EVANSTON IL 60201

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Magnetar Capital Partners LLC

(Last) (First) (Middle)
1603 ORRINGTON AVE.
13TH FLOOR

(Street)
EVANSTON IL 60201

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Supernova Management LLC

(Last) (First) (Middle)
1603 ORRINGTON AVENUE, 13TH FLOOR

(Street)
EVANSTON IL 60201

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Litowitz Alec N

(Last) (First) (Middle)
C/O MAGNETAR FINANCIAL LLC
1603 ORRINGTON AVENUE, 13TH FLOOR

(Street)
EVANSTON IL 60201

(City) (State) (Zip)
Explanation of Responses:
1. These shares of the Issuer's common stock, $.05 par value per share ("Shares"), are held for the account of Magnetar Capital Master Fund, Ltd., a Cayman Islands exempted company ("Magnetar Capital Master Fund"). Magnetar Financial LLC, a Delaware limited liability company ("Magnetar Financial"), serves as the Investment Adviser to the Magnetar Capital Master Fund. Magnetar Capital Partners LP, a Delaware limited partnership ("Magnetar Capital Partners"), serves as the sole member and parent holding company of Magnetar Financial. Magnetar Financial is a registered investment adviser under Section 203 of the Investment Advisers Act of 1940, as amended. In such capacity, Magnetar Financial exercises voting and investment power over the Shares held for the account of Magnetar Capital Master Fund. Supernova Management LLC, a Delaware limited liability company ("Supernova"), is the general partner of Magnetar Capital Partners. The manager of Supernova is Mr. Alec N. Litowitz.
2. The warrants, which are exercisable immediately at the option of the holder, are subject to certain so-called "blocker" provisions prohibiting the holder from exercising the warrants to the extent that such exercise would result in the holder being deemed the beneficial owner of more than 9.99% of the Shares then issued and outstanding.
3. The exercise price of the warrants are subject to adjustment in certain events, including certain mergers, consolidations, sales of substantially all of the Issuer's assets, subdivision or combination of the Issuer's Shares, stock dividends and other distributions by the Issuer.
4. These warrants are held for the account of Magnetar Capital Master Fund.
By: Alec N. Litowitz, as Manager of Supernova Management LLC, as General Partner of Magnetar Capital Partners LP, as Sole Member of Magnetar Financial LLC 06/28/2006
By: Alec N. Litowitz, as Manager of Supernova Management LLC, as General Partner of Magnetar Capital Partners LP 06/28/2006
By: Alec N. Litowitz, as Manager of Supernova Management LLC 06/28/2006
Alec N. Litowitz 06/28/2006
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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