SIGA TECHNOLOGIES INC — Director's Dealing 2011

May 23, 2011

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: SIGA TECHNOLOGIES INC (SIGA)
CIK: 0001010086
Period of Report: 2011-05-19

Reporting Person: Hruby Dennis E (Chief Scientific Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-05-19	Common Stock, par value $.0001 per share	M	300000	$2.50	Acquired	425000	Direct
2011-05-19	Common Stock, par value $.0001 per share	S	41300	$13.64	Disposed	383700	Direct
2011-05-20	Common Stock, par value $.0001 per share	S	188000	$13.51	Disposed	195700	Direct
2011-05-23	Common Stock, par value $.0001 per share	S	70700	$13.09	Disposed	125000	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2011-05-19	Stock Option (Right to buy)	$2.50	M	300000	Disposed	2012-07-23	Common Stock, par value $.0001 per share (300000)	Direct

Footnotes

F1: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.50 to $13.79, inclusive. The reporting person undertakes to provide to SIGA Technologies, Inc. (the "Issuer"), any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "Commission"), upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

F2: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.26 to $13.69, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

F3: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.00 to $13.31, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

F4: The option vested in equal yearly installments over a period of three (3) years, with the first 1/3 of such option vesting on July 23, 2003, the second 1/3 of such option vesting on July 23, 2004 and the remaining 1/3 of such option vesting on July 23, 2005.