US stock futures dropped Sunday evening and crude oil prices surged as investors faced two pressure points at once: ongoing uncertainty over Iran and a critical inflation report due later this week.
Futures tied to the S&P 500 slipped 0.4%, while contracts linked to the Nasdaq 100 fell 0.6%. Dow futures declined 0.3%. In energy markets, West Texas Intermediate crude jumped nearly 3% to trade near $78 a barrel, while Brent crude climbed above $81.
According to Yahoo Finance, market sentiment took a hit after President Donald Trump warned Iran of potential additional military action unless Tehran moved to rein in allied groups operating in Lebanon. Those comments came as Vice President JD Vance opened a new round of diplomatic talks with Iranian representatives in Switzerland.
Traders were already on edge heading into the week. The Federal Reserve recently struck a more hawkish tone, and markets have pushed forward expectations for the next rate hike. That makes Thursday's release of the Personal Consumption Expenditures price index a closely watched event. The PCE is the Fed's preferred measure of inflation. Economists expect core PCE, which strips out food and energy costs, to show a modest acceleration from April levels.
The combination of geopolitical tension and a potentially market-moving inflation number created a cautious mood heading into the trading week. Oil prices climbed because traders were pricing in the risk of further disruption in the Middle East, where the situation remained fluid.
Adding another layer of uncertainty is the question of Fed leadership. MarketWatch reported that Trump-selected Fed chair Kevin Warsh may hope the threat of rate hikes is enough to keep inflation in check, and that past rate-hike cycles suggest stocks could actually gain ground if hikes do materialize. Still, that analysis offers little immediate comfort to investors trying to read the short-term signals.
The Iran situation added a direct connection between foreign policy and commodity prices. When military risk rises in the Middle East, oil markets typically respond quickly, and Sunday evening was no exception. The jump in crude prices fed through to energy stocks and complicated the broader picture for inflation, since higher energy costs can push consumer prices higher even if core PCE excludes them directly.
All eyes will be on Thursday's data. If core PCE comes in hotter than expected, it could cement expectations for further tightening and put additional pressure on equities. If it shows price pressures easing, investors may find some relief. Either way, the Fed's next move remains the central question for markets heading into the second half of 2026.
