U.S. stock futures are pointing to a lower open as heightened geopolitical risks in the Middle East weigh on investor sentiment. The expiration of a 60-day ceasefire between the U.S. and Iran without an extension has sparked concerns, leading to a rise in oil prices. This risk-off sentiment is also being compounded by rising long-term Treasury yields, which are pressuring equity valuations. The decline appears to be widespread, with futures for the Dow Jones, S&P 500, and Nasdaq all trading in negative territory.