The global bond market, long a bastion of stability, is trembling under the weight of unprecedented shifts in Japan and the United States, where rising yields signal deeper concerns about inflation, fiscal sustainability, and the fragility of interconnected financial systems. Japan’s government bond market, the world’s third-largest, is experiencing a historic upheaval, with 30-year yields soaring to 3.15%—a record since their debut in 1999—and 40-year yields hitting an all-time high of 3.635%. […]