Why Aecom Stock Crashed to a 52-Week Low This Week

ACM crashed 17.9% to a 52-week low after the engineering and consulting firm disclosed a $377 million pre-tax loss on a single construction project originally signed in 2019. The hit flipped what management expected to be a profitable third quarter into a net loss of $0.65 per share, forcing the company to cut its full-year guidance.

The magnitude of the write-down caught investors off guard. While ACM's backlog stands at a record $27.8 billion—pointing to robust project demand—the loss raises execution risk questions and the potential for further charges. Management indicated the problematic project could continue dragging through mid-2027, extending uncertainty over near-term profitability.

The sharp sell-off reflects concern that a single legacy contract could obscure underlying operational performance for years. With the firm now operating under revised guidance, traders are watching whether additional project losses emerge from the backlog.