NEW YORK — The Japanese yen weakened to around 158.50 against the dollar on Aug. 10, erasing nearly half the gains from the joint U.S.-Japan intervention on July 31, when the currency briefly touched 155 from above 163.
The coordinated action by the U.S. Treasury and the Bank of Japan lifted the yen from a four-decade low. Seven days later, the currency has given back most of that ground.
Market participants have shifted focus from government-backed support to Japan's domestic policy path. The consensus: intervention alone cannot sustain a yen recovery.
Robert Sockin, chief U.S. economist at PGIM, said the action may squeeze short yen positions in the near term but is unlikely to reverse the currency's underlying weakness on its own. He warned that speculators could amplify a reversal by aggressively selling yen and U.S. Treasurys simultaneously, potentially forcing both the BoJ and the Federal Reserve into precautionary rate hikes.
Treasury Secretary Scott Bessent, in a CNBC interview last week, said intervention can send market signals but policy dictates a currency's ultimate direction. He said Washington joined the effort because of optimism about Japan's policy path.
The rare joint move to support a major currency reflected concern that persistent yen weakness could worsen inflation in Japan and pressure other Asian currencies.
The yen has underperformed all its Group-of-10 peers this month, repeating a pattern from May, when the currency lagged despite record Japanese government spending to prop it up.
Bank of America said the central banks' short-term objective was to push the yen through the 155 level — a threshold that held only briefly before the current retreat.
If the BoJ is forced to tighten policy to defend the currency, Japanese government bond yields would rise directly, with knock-on effects across global yield curves and duration-sensitive portfolios. Without a meaningful shift in interest rate differentials, the yen faces continued pressure regardless of past intervention.
