Amentum is trading 4.25% up at $18.90 on October 15, 2026, as markets rotated toward value-oriented stocks amid inflation and interest-rate concerns. - The Dow rose 1.14%; the S&P 500 gained 0.33% and the Nasdaq 0.04%. Bloomberg-described trading showed most S&P 500 stocks rising as technology shares lagged. - No clearly timed company-specific catalyst emerged: the $572.4 million Cheyenne Mountain contract was announced in September, and the reported Wall Street Zen upgrade was published Sunday.