Robin E. Abrams - Jul 31, 2021 Form 4 Insider Report for SIGA TECHNOLOGIES INC (SIGA)

Role: General Counsel and CAO
Signature: /s/ Robin E. Abrams
Stock symbol: SIGA
Transactions as of: Jul 31, 2021
Transactions value $: -$71,987
Form type: 4
Date filed: 8/3/2021, 04:05 PM

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	SIGA	Common Stock, Par Value $.0001 Per Share	Options Exercise	$0	+26.7K	+77.47%	$0.00	61.1K	Jul 31, 2021	Direct
transaction	SIGA	Common Stock, Par Value $.0001 Per Share	Tax liability	-$72K	-11.3K	-18.5%	$6.37	49.8K	Jul 31, 2021	Direct	F1

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	SIGA	Restricted Stock Units	Options Exercise	$0	-26.7K	-100%	$0.00^*	0	Jul 31, 2021	Common Stock, Par Value $.0001 Per Share	26.7K		Direct	F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Represents the withholding by SIGA Technologies, Inc. of shares of Common Stock (based on $6.37 per share, the closing stock price on July 30, 2021) to satisfy tax withholding obligations associated with the vesting of restricted stock units ("RSUs") and the consequent issuance of Common Stock.
F2	RSUs represent contingent rights to receive Common Stock on a one-for-one basis. The RSUs were granted on July 31, 2019 and vested over two years, with the first 1/2 of such RSUs vesting on July 31, 2020 and the remaining 1/2 of such RSUs vesting on July 31, 2021.