Archer Aviation is trading 4.01% down at $5.38 on September 28, 2026, amid broader weakness and likely risk-off pressure from rising oil prices, Treasury yields and geopolitical tension; no clear company-specific catalyst surfaced. - The Nasdaq was down 0.87% and the S&P 500 was down 0.61%. - The latest company news was a September 24 announcement that the antitrust waiting period had expired for its planned Boeing-unit acquisitions. - Volume information was unavailable.