SIGA TECHNOLOGIES INC — Director's Dealing 2011

May 20, 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: CONSTANCE THOMAS E (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2011-05-19	Common Stock, par value $.0001 per share	S	16267	$14.00	Disposed	195000	Direct
2011-05-19	Common Stock, par value $.0001 per share	S	10000	$14.07	Disposed	185000	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 $14.00 to $14.02, 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 "SEC"), 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 $14.02 to $14.18, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.