US stock markets today (March 27, 2026): S&P 500, Dow fall as oil rises above $100; Iran war uncertainty weighs on sentiment

US equities traded lower on Friday, heading toward their longest weekly losing streak in nearly four years, as investors grappled with rising oil prices and persistent uncertainty around the Iran conflict, AP reported.Major indices slipped in early deals, with the S&P 500 down 0.8%, the Dow Jones Industrial Average losing 402 points or 0.9%, and the Nasdaq Composite falling 1%, AP reported. The weakness follows a volatile week marked by alternating gains and losses, reflecting shifting expectations around a possible de-escalation.Hopes briefly improved after US President Donald Trump pushed back his deadline to April 6 for potential military action tied to Iran’s control over the Strait of Hormuz. However, the optimism proved short-lived as hostilities continued and no concrete diplomatic progress emerged.Crude prices, which initially softened after the announcement, moved higher again through the day. Brent crude climbed 2.2% to $104.15 per barrel, while US crude advanced 3% to $97.28. Prices have risen sharply from around $70 levels seen before the conflict began.“The diplomatic dissonance this week between the US and Iran dismayed investors,” said Doug Beath of Wells Fargo Investment Institute. “By the end of the week, risk appetite could not withstand the fog of war.”Echoing the sentiment, Jim Bianco of Bianco Research said market participants are increasingly dismissing signals from Washington. “Any further statements by Trump about a deal are white noise to the markets. Only if the IRANIANS say the talks are going well will it impact markets.”The prolonged conflict has heightened fears of disruptions to energy supplies from the Persian Gulf, a key global transit route. Analysts at Macquarie warned that oil prices could spike to $200 per barrel if tensions persist into the summer.Elevated crude prices have also pushed bond yields higher, complicating the outlook for monetary policy. The yield on the 10-year US Treasury rose to 4.46%, up from 4.42% the previous day and significantly above levels seen before the conflict escalated.Higher yields have already translated into increased borrowing costs across the economy, including mortgages and corporate loans, raising concerns about growth.Market breadth remained weak, with the majority of stocks in the S&P 500 trading in negative territory. One of the few bright spots was Netflix, which gained 0.8% after announcing a price increase for its services.Elsewhere, European markets moved lower, while Asian indices closed on a mixed note, underscoring the cautious global mood.