Trump rejects Iran proposal; OpenAI pause weighs on tech - what’s moving markets
September 28, 2026
U.S. stock futures moved lower on Monday as investors assessed renewed U.S.-Iran tensions, rising crude oil prices and fresh concerns surrounding the pace of artificial intelligence development. President Donald Trump’s rejection of an Iranian proposal concerning the reopening of the Strait of Hormuz added to energy-market uncertainty, while OpenAI’s reported pause in training some advanced AI models pressured technology sentiment.
The developments put U.S. stock market futures, oil prices, technology stocks, artificial intelligence companies and global financial markets in focus as investors assess the potential impact on inflation, interest rates and corporate valuations.
U.S. Stock Futures Slip as Oil and Technology Concerns Increase
U.S. equity futures declined during early Monday trading as markets reacted to two major themes: renewed uncertainty surrounding the Iran conflict and concerns about the outlook for advanced artificial intelligence development.
Around 03:50 ET, S&P 500 futures were down 0.42% at 7,710.7, while Nasdaq 100 futures declined around 1% to 30,595. Dow Jones futures were also lower. The weakness followed concerns that higher energy prices and uncertainty around AI investment could weigh on risk-sensitive assets.
Technology shares remained particularly sensitive because the AI sector has become an important driver of investment in semiconductors, cloud computing, data centers and related infrastructure.
Iran-US Tensions Keep Strait of Hormuz in Focus
Energy markets are closely watching developments involving Iran, the United States and the Strait of Hormuz, a strategically important route for global oil shipments.
Iran has maintained conditions linked to reopening the waterway, while Trump rejected Tehran's proposal. Reuters reported that oil prices subsequently rebounded as markets assessed the possibility of continued disruption to energy transportation.
The longer uncertainty surrounding the Strait of Hormuz continues, the greater the potential pressure on global crude oil supply, energy prices, transportation costs and inflation expectations.
Oil Prices Rise Above $100
Crude oil remained one of the biggest market movers on Monday.
Brent crude futures rose above $105 per barrel, while WTI crude also advanced as traders monitored the potential impact of disruptions around the Strait of Hormuz. Reuters separately reported Brent at $106.14 per barrel and WTI at $93.55 in early trading.
Oil prices above the $100 level are attracting particular attention because sustained increases in crude can raise fuel and transportation costs and contribute to broader inflation pressures.
For investors, the key oil-market indicators to watch include Brent crude, WTI crude, global oil supply, Middle East shipping activity, Iranian oil exports and Strait of Hormuz developments.
OpenAI Pause Raises Questions for AI Investment
The other major market theme is artificial intelligence.
OpenAI's decision to pause training on some advanced AI models has contributed to weaker sentiment across parts of the technology and semiconductor sectors. Investors are watching whether the development affects the pace of AI investment and demand for the infrastructure supporting the sector.
The AI investment cycle has supported significant demand for AI chips, semiconductors, cloud computing, data centers and advanced computing infrastructure. Any change in expectations around AI development could therefore have implications across the broader technology supply chain.
Why Higher Oil Prices Matter for Stock Markets
A prolonged increase in crude oil prices can have several consequences for financial markets.
Higher energy costs can increase expenses for transportation companies, manufacturers and other businesses. If higher energy prices contribute to persistent inflation, markets may also reassess expectations for central bank interest-rate cuts.
This creates an important connection between oil prices, inflation, interest rates and stock market valuations.
Energy producers can benefit from higher crude prices, while companies with significant fuel or transportation costs may face greater expense pressures.
Key Markets to Watch Today
Investors and market participants are monitoring several major indicators:
Brent crude oil prices
WTI crude oil prices
S&P 500 futures
Nasdaq 100 futures
Dow Jones futures
Technology and semiconductor stocks
AI-related companies
U.S. Treasury yields
Global inflation expectations
U.S.-Iran diplomatic developments
Strait of Hormuz shipping activity
Global oil supply and energy markets
Market Outlook
The combination of geopolitical uncertainty, higher oil prices and changing expectations around artificial intelligence investment is creating a closely watched environment for global financial markets.
For the stock market, investors will continue monitoring whether higher energy prices persist and how technology companies respond to developments in AI. For commodity markets, the focus remains on crude oil supply, the Strait of Hormuz and developments involving Iran and the United States.