The Bank of Japan's rate increase and foreign-exchange rate check failed to prevent the yen from weakening to about 158.4 per dollar in New York trading on Sept. 23. The BOJ lifted its policy rate by 0.25 percentage point to 1.25% from 1.0% on Sept. 18, briefly supporting the yen alongside expectations for further tightening and possible currency intervention. That effect faded as stronger-than-expected U.S. purchasing managers' index (PMI, survey of business activity) data, renewed inflation concerns and weak demand at a five-year Treasury auction pushed U.S. yields higher. Markets priced in a roughly 70% chance of another Federal Reserve rate increase at the Oct. 27-28 Federal Open Market Committee meeting, up from about 55% a day earlier. With the U.S. 10-year yield reaching 5.13%, its highest level since July 2007 and in 19 years and two months, investors increasingly viewed U.S. rates and dollar direction as stronger yen drivers than Japanese monetary policy. The yen's decline has remained volatile, moving from nearly 160 per dollar in late August and early September to the 152 range before weakening again. Markets remain alert to possible yen-buying intervention, although dollar strength against the euro and other major currencies suggests Japanese authorities may struggle to reverse the decline alone.