S&P 500 futures edge up as Iran deal talks roil oil markets

S&P 500 futures edged up slightly as traders weighed whether a U.S.-Iran deal could push oil lower and eventually ease pressure on gasoline prices and inflation. The move came after President Donald Trump said negotiations with Iran were in the "final stages," a signal that helped drive U.S. crude down $5.89 to $98.26 a barrel and Brent down $6.26 to $105.02 on May 21. The 10-year Treasury yield fell 9.4 basis points to 4.576%, showing how quickly bond markets were repricing the chance of less geopolitical risk and slower inflation pressure from energy.

Oil stayed volatile the next day as investors tried to separate diplomatic headlines from a workable agreement. Brent settled at $102.58 and West Texas Intermediate at $96.35, both near two-week lows, but the market was still struggling with uncertainty over the talks and what any deal would mean for exports through the Middle East. If crude stays under pressure, refiners could eventually face lower input costs, which is the channel that could feed into cheaper gasoline for U.S. drivers. But that relief would depend on more than headlines: the market needs a durable agreement and confidence that supply routes remain open.

The latest swings fit a pattern that has repeated all month. Earlier in May, oil prices plunged as much as 15% intraday after reports that Washington believed it was nearing a deal with Tehran. On May 6, the S&P 500 closed up 1.5% and the Nasdaq Composite rose 2% after that report, while U.S. crude briefly fell to about $88 a barrel and Brent to about $96 before easing back. The message from traders was blunt: any hint of de-escalation can move stocks, bonds and energy prices almost immediately.

The biggest pressure point remains the Strait of Hormuz, which Reuters reported carried oil and liquefied natural gas shipments equal to about 20% of global consumption before the war. Pakistan has been acting as a mediator in the discussions, while Rubio said a proposed tolling system in the strait would make a diplomatic deal unfeasible. Iran has also signaled steps to entrench control of the waterway, underscoring how much of the market reaction still hinges on whether barrels can keep moving without disruption.

For now, the rally in futures reflects hope, not certainty. A real break for motorists would require lower crude to stick, risk premia to fade and the Strait of Hormuz to remain open enough for global supply to flow without a new shock.