US stocks: S&P 500, Nasdaq close lower, dragged by Alphabet and megacap tech; focus on Iran

US markets ended mixed with the S&P 500 and Nasdaq closing lower, dragged down by Alphabet and megacap tech stocks amid investor concerns over AI spending. The Dow edged higher on gains in healthcare and industrial stocks. Falling oil prices offered some relief, but a hawkish Federal Reserve stance and upcoming inflation data kept investors cautious about future rate hikes.