The S&P 500 is trading lower due to a confluence of negative factors. Renewed geopolitical tensions in the Middle East, including a reported Iranian attack on a U.S. base, have caused a significant spike in oil prices, fueling inflation and economic uncertainty. Adding to the downward pressure is a continued sell-off in the semiconductor sector, as investors question the short-term profitability of AI-related investments. The market is also in a cautious stance ahead of the Federal Reserve's interest rate decision later today.