Schiffer Vivienne 4

What Happened
Vivienne Schiffer, SVP, Chief Legal Officer, Chief Compliance Officer & Corporate Secretary of Great Lakes Dredge & Dock Corp (GLDD), was awarded a total of 24,667 performance-based restricted stock units (RSUs) that vested on March 16, 2026 (14,213 from a 3/15/2023 grant and 10,454 from a 3/15/2024 grant). To satisfy tax withholding obligations, 10,125 of those shares were withheld at $16.93 per share, producing proceeds of about $171,417. Net new shares retained by Schiffer after withholding equal 14,542 shares.

Key Details

• Transaction date: 2026-03-16; Form 4 filed 2026-03-18 (filed within the usual two-business-day window).
• Awards received: 14,213 shares (performance RSUs from 3/15/2023) and 10,454 shares (performance RSUs from 3/15/2024).
• Shares withheld for taxes (dispositions): 2,060; 3,461; 2,058; 2,546 — total 10,125 shares at $16.93 each; aggregate value reported ≈ $171,417.
• Net newly acquired/retained shares: 24,667 awarded − 10,125 withheld = 14,542 shares.
• Shares owned following transaction: not specified in the filing.
• Codes: A = award/grant/acquisition; F = payment of exercise price or tax liability (share withholding). Footnotes confirm these were performance-based RSUs that vested upon satisfaction of performance conditions.

Context
This was not an open-market purchase or a sale for investment reasons; it reflects vesting of performance RSUs and routine share withholding to cover taxes (a common administrative action). Such awards increase insider ownership when net shares are retained, but do not necessarily indicate buying or selling intent.