Nguyen Diem 4

4 · SIGA TECHNOLOGIES INC · Filed Mar 17, 2026

AI-generated summary of this filing

Updated Mar 17, 2026

SIGA CEO Nguyen Diem Receives RSUs; Withholds Shares for Taxes

What Happened

Nguyen Diem, CEO of SIGA Technologies (SIGA), had restricted stock units (RSUs) vest and convert into common stock on March 13, 2026. The filing shows 85,045 derivative shares converted (exercise/conversion) and a related withholding of 47,029 shares at $5.26 per share to satisfy tax obligations (withheld value $247,373). The report also records a derivative award entry of 272,243 RSUs (see footnotes).
This was not an open‑market sale by the CEO but a routine vesting event with shares withheld to cover taxes.

Key Details

Transaction date: March 13, 2026; Form 4 filed March 17, 2026 (timely).
Withholding price: $5.26 per share (closing price on 3/13/2026); tax withholding amount = $247,373 for 47,029 shares.
Reported derivative activity: 85,045 shares converted (M code) and 272,243 RSUs recorded as an award (A code).
Shares owned after transaction: Not specified in the provided excerpt of the filing.
Footnotes:
- F1: The acquired common stock resulted from the vesting of one‑third of RSUs granted on March 13, 2025.
- F2: The issuer withheld shares to satisfy tax withholding obligations, calculated at $5.26/share.
- F3: RSUs vest one‑third on each of the first three anniversaries of the grant date.
Filing timeliness: Filed within the required reporting window (timely).

Context

RSUs convert to common stock on vesting; the withholding of shares to cover taxes is a common, administrative step and not the same as an open‑market sale. The filing shows a net increase in owned shares for the insider after withholding (conversion minus shares withheld), though exact post‑transaction holdings are not disclosed here.
These entries reflect equity compensation vesting and tax coverage, not discretionary purchases or market sales by the CEO.

Form 4

Period: 2026-03-13

DirectorChief Executive Officer

Transactions

Exercise/Conversion
Common Stock, par value $.0001 per share
[F1]
2026-03-13+85,045→ 185,796 total
Tax Payment
Common Stock, par value $.0001 per share
[F2]
2026-03-13$5.26/sh−47,029$247,373→ 138,767 total
Exercise/Conversion
Restricted Stock Units
[F3]
2026-03-13−85,045→ 170,092 total
→ Common Stock, par value $.0001 per share (85,045 underlying)
Award
Restricted Stock Units
[F3]
2026-03-13+272,243→ 272,243 total
→ Common Stock, par value $.0001 per share (272,243 underlying)

Footnotes (3)

[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.

Signature

/s/ Diem Nguyen|2026-03-17

1 file