SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* MacAndrews & Forbes Holdings Inc. (Last) (First) (Middle) 35 EAST 62ND STREET (Street) NEW YORK NY 10065 (City) (State) (Zip)	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)
	3. Date of Earliest Transaction (Month/Day/Year) 01/07/2011
	4. 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 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	01/07/2011		X		697,765(1)	A	$1.8288(1)	9,348,935	I	Owned through wholly-owned corporation
Common Stock, par value $.0001 per share	01/07/2011		F		95,066(2)	D	$13.423(2)	9,253,869	I	Owned through wholly-owned corporation
Common Stock, par value $.0001 per share								3,851,969	I	Owned through partially-owned limited partnership

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 Securities Underlying Derivative Security (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: 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)	$1.8288(3)	01/07/2011		X			697,765(3)	01/08/2004	01/08/2011	Common Stock	697,765(3)	$0.00	0	I	Owned through wholly-owned corporation

1. Name and Address of Reporting Person* MacAndrews & Forbes Holdings Inc. (Last) (First) (Middle) 35 EAST 62ND STREET (Street) NEW YORK NY 10065 (City) (State) (Zip)

1. Name and Address of Reporting Person* PERELMAN RONALD O (Last) (First) (Middle) 35 EAST 62ND STREET (Street) NEW YORK NY 10065 (City) (State) (Zip)

1. Name and Address of Reporting Person* MacAndrews & Forbes LLC (Last) (First) (Middle) 35 EAST 62ND STREET (Street) NEW YORK NY 10065 (City) (State) (Zip)

1. Name and Address of Reporting Person* STH Partners, L.P. (Last) (First) (Middle) C/O MATTHEW H. KAMENS, COZEN O'CONNOR 1900 MARKET STREET (Street) PHILADELPHIA PA 19103 (City) (State) (Zip)

Explanation of Responses:

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 697,765 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 on January 8, 2004 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 639,095 shares of Common Stock at an exercise price of $2.00 per share, but, pursuant to the anti-dilution provisions of the warrants, were adjusted to reflect the effects of certain of SIGA's subsequent issuances.

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.

	/s/ Barry F. Schwartz, Executive Vice Chairman	01/11/2011
	/s/ Barry F. Schwartz for Ronald O. Perelman pursuant to a Power of Attorney filed with the Securities and Exchange Commission	01/11/2011
	/s/ Barry F. Schwartz, Executive Vice Chairman	01/11/2011
	/s/ Paul G. Savas, Executive Vice President	01/11/2011
	** Signature of Reporting Person	Date
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