US stock market today: Why S&P 500 and Nasdaq are down while Dow gains as defense stocks surge on Trump’s $1.5 trillion budget push

US stock market showed a sharp divide today, January 8, 2026. The Dow Jones rose 60.94 points to 49,057.02 as defense giants soared. However, the S&P 500 fell 0.25% and the Nasdaq dropped 0.93%. A massive $1.5 trillion defense budget proposal from President Trump ignited aerospace gains, while "AI fatigue" and high valuations dragged down major technology shares like Meta and Oracle.