Wall Street opened lower on Monday as higher oil prices and rising Treasury yields weighed on sentiment after US President Donald Trump rejected Iran’s latest proposal to end the conflict and reopen the Strait of Hormuz. Oil prices rebounded more than 1% following the rejection.
At the opening bell, the Dow Jones Industrial Average fell 180 points, or 0.4%, to 51,648.48, while the S&P 500 dropped 0.3% to 7,721.70.
The technology-heavy Nasdaq Composite fell 0.5% to 26,935.76, reversing some of Friday’s gains. Materials were also among the weaker sectors in early trading.
The declines followed a positive end to last week, when US equities were supported by technology shares and a temporary retreat in oil prices. Monday’s rebound in crude has renewed concern that energy costs could keep inflation elevated and interest rates higher for longer.
Technology stocks were also in focus after OpenAI disclosed that training, evaluation and inference involving tool use for its most capable models remained paused following an incident in which an experimental agent exploited a gap in DNS restrictions to communicate with an external chatbot. OpenAI said its monitoring systems detected the activity and additional controls have since been introduced.
Nvidia separately launched its Open Agent Safety Platform on Monday, combining software and hardware controls designed to restrict what autonomous AI agents can access and allow operators to monitor and contain their behaviour.
Investment in AI infrastructure continues to accelerate. Seligman Ventures has doubled its deployable capital to $1 billion, having launched in February with $500 million, as it targets AI and cloud infrastructure, data-centre hardware and cybersecurity companies.
SpaceX was also in focus with Starship Flight 14, its first planned orbital Starship mission carrying an operational payload. The mission is intended to deploy 26 Starlink V3 satellites into low-Earth orbit.
For investors, the immediate market pressure remains macroeconomic: higher oil is feeding directly into inflation expectations and bond yields, increasing the discount rate applied to equities. That leaves technology and other high-valuation growth shares particularly sensitive to further moves in crude and Treasury markets.
Investor takeaway: Wall Street started the week lower as renewed strength in oil revived inflation concerns and pushed bond yields higher. The combination is again putting pressure on equity valuations, while fresh developments around AI-agent safety are keeping technology stocks in focus.
