US stock futures fell before the August 18 opening bell as rising Treasury yields and oil prices renewed concerns about the macroeconomic backdrop. The Nasdaq 100 dropped 1.4% and the S&P 500 fell 0.6%, while the 30-year Treasury yield reached its highest level since 2007. The 10-year yield also moved toward levels not seen since early 2025. Brent crude traded near $91 per barrel as hopes for near-term peace in the Middle East faded, adding to inflation concerns and potentially complicating the Federal Reserve's monetary-policy outlook. Technology and AI-related stocks led the decline because higher yields reduce the present value of expected future earnings, while energy shares showed relative resilience as higher oil prices support producers' revenue. The US Treasury announced plans to double its bond buyback program in September, focusing on longer-dated Treasuries to help stabilize that part of the market. The announcement provided only brief relief before yields resumed climbing. The technology and AI trade now faces a stress test after valuations were built around expectations for moderating rates and falling inflation. Overall market reactions showed mixed follow-through after the initial declines.