US stock futures pointed to a weaker opening on Tuesday, as rising oil prices, higher global bond yields and renewed US-Iran tensions weighed on investor sentiment. Dow Jones Industrial Average futures fell 240 points, or 0.5%, while S&P 500 futures declined 0.5%. Nasdaq-100 futures underperformed, slipping nearly 1%, signalling pressure on technology stocks at the start of the new month.

The weakness comes as investors assess whether elevated energy prices could keep inflationary pressures high and complicate the Federal Reserve's monetary policy outlook.

The weakness in futures was reflected across major technology stocks. Nvidia, AMD and Micron were all down more than 1% in pre-market trading. Microsoft fell 1%, while Google-parent Alphabet slipped 0.6%.

The decline comes after a strong August for US technology stocks, with AI-linked companies among the market's leading performers. September has historically been a challenging month for equities, adding another reason for investors to remain cautious as the new month begins.

Global bond yields continued to climb, raising concerns that persistent inflation could limit the Federal Reserve's ability to ease monetary policy later this month. The yield on the US 10-year Treasury note climbed to levels not seen since January 2025. Japan's 10-year government bond yield reached its highest level since August 1996, while Germany's benchmark yield rose to its highest level since 2011.

Investors are increasingly concerned that higher oil prices could feed into inflation, keeping central banks cautious on interest-rate cuts. The rise in yields is particularly significant for growth and technology stocks, whose valuations are more sensitive to changes in borrowing costs and discount rates.