Diem Nguyen - 13 Mar 2026 Form 4 Insider Report for SIGA TECHNOLOGIES INC (SIGA)

Role: Chief Executive Officer, Director
Signature: /s/ Diem Nguyen
Issuer symbol: SIGA
Transactions as of: 13 Mar 2026
Net transactions value: $0
Form type: 4
Filing time: 17 Mar 2026, 16:05:46 UTC
Previous filing: 28 Jan 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Nguyen Diem	Chief Executive Officer, Director	C/O SIGA TECHNOLOGIES, INC., 31 EAST 62ND STREET, NEW YORK	/s/ Diem Nguyen	17 Mar 2026	0001814338

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		+85,045	+84%	$0.000000^*	185,796	13 Mar 2026	Direct	F1
transaction	SIGA	Common Stock, par value $.0001 per share	Tax liability		-47,029	-25%	$5.26^*	138,767	13 Mar 2026	Direct	F2

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		-85,045	-33%	$0.000000^*	170,092	13 Mar 2026	Common Stock, par value $.0001 per share	85,045		Direct	F3
transaction	SIGA	Restricted Stock Units	Award		+272,243		$0.000000^*	272,243	13 Mar 2026	Common Stock, par value $.0001 per share	272,243		Direct	F3

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

Explanation of Responses:

Id	Content
F1	Represents the acquisition of Common Stock from the vesting of one-third of the restricted stock units ("RSUs") granted on March 13, 2025.
F2	Represents the withholding by the Issuer of shares of Common Stock (based on $5.26 per share, the closing stock price on March 13, 2026) to satisfy tax withholding obligations associated with the vesting of RSUs and the consequent issuance of Common Stock.
F3	RSUs represent contingent rights to receive Common Stock on a one-for-one basis. The RSUs vest over three years, one-third on each of the first three anniversaries of the date of grant.