Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0287
Expires: January 31, 2005
Estimated average burden hours per response... 0.5

(Print or Type Responses)
1. Name and Address of Reporting Person *
MacAndrews & Forbes Holdings Inc.
   2. Issuer Name and Ticker or Trading Symbol
SIGA TECHNOLOGIES INC [SIGA] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
35 EAST 62ND STREET, 		 3. Date of Earliest Transaction (Month/Day/Year)
08/13/2010
(Street)

NEW YORK, NY 10065		 4. If Amendment, Date 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
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock, par value $.0001 per share 08/13/2010   X   358,862 (1) A $ 1.9 (1) 8,118,280 I Owned through wholly-owned corporation
Common Stock, par value $.0001 per share 08/13/2010   D   82,924 (2) D $ 8.2225 (2) 8,035,356 I Owned through wholly-owned corporation
Common Stock, par value $.0001 per share               3,851,969 I Owned through partially-owned limited partnership

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number. SEC 1474 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Warrant (Right to Buy) $ 1.9 (3) 08/13/2010   X     358,862 (3) 08/13/2003 08/13/2010 Common Stock 358,862 (3) $ 0 0 I Owned through wholly-owned corporation

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
MacAndrews & Forbes Holdings Inc.
35 EAST 62ND STREET
NEW YORK, NY 10065		   X   X    
PERELMAN RONALD O
35 EAST 62ND STREET
NEW YORK, NY 10065		   X   X    
MacAndrews & Forbes LLC
35 EAST 62ND STREET
NEW YORK, NY 10065		   X   X    
STH Partners, L.P.
C/O MATTHEW H. KAMENS, COZEN O'CONNOR
1900 MARKET STREET
PHILADELPHIA, PA 19103		   X   X    

Signatures

 /s/ Barry F. Schwartz, Executive Vice Chairman   08/17/2010
**Signature of Reporting Person Date
 /s/ Barry F. Schwartz for Ronald O. Perelman pursuant to a Power of Attorney filed with the Securities and Exchange Commission   08/17/2010
**Signature of Reporting Person Date
 /s/ Barry F. Schwartz, Executive Vice Chairman   08/17/2010
**Signature of Reporting Person Date
 /s/ Paul G. Savas, Executive Vice President   08/17/2010
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(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).
(1) Acquired pursuant to the exercise of the warrants described in Table II.
(2) The shares represent the exercise price paid by MacAndrews & Forbes LLC (formerly known as MacAndrews & Forbes Holdings Inc.) ("MacAndrews & Forbes") to acquire the 358,862 shares reported above. The price of the shares was calculated pursuant to the terms of the warrant.
(3) These warrants to purchase shares of the common stock ("Common Stock") of SIGA Technologies, Inc. ("SIGA") were acquired by MacAndrews & Forbes pursuant to a Securities Purchase Agreement, dated August 13, 2003, by and between SIGA and MacAndrews & Forbes. These warrants were previously reported at the time of acquisition as the right to buy 341,493 shares of Common Stock at an exercise price of $2.00 per share, but, pursuant to the terms of the warrants, were adjusted to reflect the effects of SIGA's subsequent issuance to certain third parties.
 
Remarks:
Ronald O. Perelman beneficially owns 100% of the common stock of MacAndrews & Forbes Holdings Inc., which beneficially owns 100% of the equity interests of MacAndrews & Forbes, a joint filer hereunder.  MacAndrews & Forbes has a direct ownership interest in STH Partners, L.P., a joint filer hereunder ("STH").  MacAndrews & Forbes beneficially owns the securities described above as owned through wholly-owned corporation and STH beneficially owns the securities described above as owned through partially-owned limited partnership.  STH has agreed that any voting stock of SIGA held by STH will be voted in the same proportion as the votes cast by the other holders of voting stock of SIGA on any matter to be voted on by holders of such voting stock.  Paul G. Savas and Steven L. Fasman serve as the representatives of the reporting persons on SIGA's board of directors.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.