Japanese Institutions' U.S. Bond Holdings Create Cross-Market Transmission Risk

Japanese life insurers, regional banks, and major asset managers hold substantial U.S. Treasury exposure alongside domestic JGB portfolios. When U.S. Treasury prices halt rallies—as occurred Friday after an eight-day run—the repricing of dollar-denominated duration feeds directly into yen-denominated hedging costs. This shifts institutional appetite for unhedged foreign bonds, creating feedback loops that amplify yield moves between the two markets. The mechanism amplifies spillovers beyond what mechanical correlation alone would predict.