Japanese yen hits 40‑year low as authorities shift to surprise intervention tactics

The Japanese yen fell to ¥162.66 per dollar, its weakest level since 1986, as a widening interest‑rate gap – the Bank of Japan’s 1 % policy rate versus the U.S. Federal Reserve’s 3.5‑3.75 % range – drove investors toward the dollar. Record‑size market moves saw the Ministry of Finance spend a historic ¥11.7 trillion ($72 billion) intervening in late April‑early May, but the boost was short‑lived.

Sources say the ministry is abandoning previous “jaw‑boning” warnings and will instead act silently, targeting speculative short‑yen positions without announcing a specific exchange‑rate trigger. The aim is to make short‑selling riskier and to prevent traders from unwinding before any intervention. Finance Minister Satsuki Katayama and top currency diplomat Atsushi Mimura have refrained from public comments, signalling a new “ambush” approach.

Officials warn that a weak yen raises import costs and could lift underlying inflation, while a sudden rise in the yen would put pressure on U.S. Treasury yields and global equity markets. Market participants are watching upcoming U.S. jobs data for clues on the dollar’s direction, which could influence the timing of any further Japanese action.