Bond yields across the United States, Europe and Japan surged to multi-decade highs on October 1 as higher energy prices linked to the Iran war, expanded artificial-intelligence investment and resilient growth strengthened expectations that interest rates will remain elevated. The 10-year U.S. Treasury yield, a global benchmark, reached 5.34%, its highest level since April 3, 2002, before retreating to about 5.26% as bargain hunters bought Treasuries. The UK 30-year yield exceeded 6%, its highest level since 1998, while France’s 10-year yield approached 5%, a level last seen in 2002. Rising yields increase borrowing and refinancing costs for governments, companies and households. The Institute of International Finance estimated that advanced economies paid more than $3.3 trillion in interest on internationally traded government bonds over the past year. In the United States, the bond-market shock pressured stocks early before the major indexes recovered slightly. The Dow rose 20.51 points, or 0.04%, to 50,926.56; the S&P 500 gained 14.91 points, or 0.19%, to 7,666.45; and the Nasdaq Composite advanced 10.53 points, or 0.04%, to 26,871.60. Higher oil prices, stronger manufacturing cost pressures and persistent labor-market resilience continued to complicate the Federal Reserve’s policy outlook. The yield surge also added a political risk for the Trump administration ahead of midterm elections, as voters confront higher energy, mortgage and other borrowing costs.