X0306 4 2014-01-03 0 0001010086 SIGA TECHNOLOGIES INC SIGA 0001551452 Haynes William J II C/O SIGA TECHNOLOGIES, INC. 660 MADISON AVENUE, SUITE 1700 NEW YORK NY 10065 0 1 0 0 Executive VP & General Counsel Common Stock, par value $.0001 per share 2014-01-03 4 M 0 25000 0 A 25000 D Common Stock, par value $.0001 per share 2014-01-03 4 F 0 11063 3.35 D 13937 D Restricted Stock Units 2014-01-03 4 M 0 25000 0 D Common Stock, par value $.0001 per share 25000 50000 D Restricted Stock Units 2014-01-03 4 A 0 75000 0 A Common Stock, par value $.0001 per share 75000 75000 D SIGA Technologies, Inc. (the "Issuer") has certain tax withholding obligations associated with the vesting of restricted stock units ("RSUs") and the consequent issuance of Common Stock of the Issuer. This Form 4 reports the surrender to the Issuer by the Reporting Person of 11,063 shares of Common Stock -- granted in the form of RSUs approximately one year ago -- in order to satisfy those withholding tax obligations. The Reporting Person reported the initial grant on January 7, 2013. Represents vesting of one-third of RSUs granted on January 3, 2013. The second 1/3 of such RSUs vest on January 3, 2015 and the remaining 1/3 of such RSUs vest on January 3, 2016. Each RSU converts into one share of Common Stock of the Issuer on a one for one basis. The RSUs vest in equal yearly installments over a period of three (3) years, with the first 1/3 of such RSUs vesting on January 3, 2015, the second 1/3 of such RSUs vesting on January 3, 2016 and the remaining 1/3 of such RSUs vesting on January 3, 2017. Each RSU converts into one share of Common Stock of the Issuer on a one for one basis. /s/ William J. Haynes II 2014-01-07