Tetra Tech is trading at $42.93, up 4.86%, after-hours on November 4 following a broad U.S. market rally after Democrats won control of Congress. - Investors responded to reduced political uncertainty and anticipated legislative gridlock. - No company-specific announcement explaining the move was found; fiscal 2026 results are scheduled for November 11 after market close. - Shares gained 3.88% in the regular session on November 4 before the additional after-hours move.