Japan’s 10-year government bond yield climbed to its highest level since 1999 after Iran effectively shut down tanker traffic through the Strait of Hormuz, sending oil prices above $113 per barrel and forcing Tokyo to tap its strategic reserves at a record pace.
Key Takeaways:
Japan’s 10-year bond yield hit 2.39% by early April 2026, its highest level since 1999, as Iran’s Hormuz blockade fueled inflation fears. The Bank of Japan faces a rate hike decision at its April 27-28 meeting, with markets pricing in a 60-70% probability of action. Japan pledged a record 80 million barrel reserve release, but analysts warn prolonged disruption risks stagflation and global market volatility. Iran’s Strait of Hormuz Blockade Triggers Japan Bond Market AlarmHigher rates would close a chapter on ultra-loose monetary policy that has defined Japan since the 1990s bubble. Major life insurers are already sitting on roughly $60 billion in unrealized losses on Japanese government bond holdings.
The spillovers stretch beyond Tokyo. Japan holds $1.225 trillion in U.S. Treasuries as of January 2026, making it the largest foreign holder. As domestic yields rise, appetite for foreign bonds falls. That puts upward pressure on U.S. borrowing costs.
