US stocks today: Nasdaq, S&P 500 rise as Nvidia revives AI rally; Fed outlook in focus

Nvidia's strong revenue forecast revived the AI trade and lifted the Nasdaq and S&P 500, but Wall Street's focus is quickly shifting to Fed Chair Kevin Warsh's Jackson Hole speech. Fresh inflation data and a resilient labour market have complicated the interest rate outlook, leaving investors weighing AI optimism against monetary policy risks.