WLDN ▼ -0.4% - Willdan Group, Inc. $WLDN - Willdan to Acquire Mantis Innovation, Strengthening Its Position in Energy Management and Infrastructure Willdan Group announced an acquisition of Mantis Innovation to expand its capabilities in energy management and infrastructure services, though the stock declined 0.4% on the news, suggesting investors may be awaiting details on deal terms and integration costs. 22-SEP-2026 04:16 PM ET