US stock markets, including the S&P 500, Nasdaq, and Dow Jones, concluded 2025 with significant double-digit gains, marking a third consecutive year of bull run for the S&P 500. Trading was closed on New Year's Day, January 1, 2026, with regular sessions resuming on January 2. Investors are now focusing on portfolio adjustments, geopolitical tensions, market valuations, and the future of AI trade in 2026, anticipating continued but potentially more volatile market performance.