The Japanese yen weakened to 157.44 per U.S. dollar on Monday, down about 0.36% on the session, as traders returned their attention to the risk of another Japanese currency intervention only days after the Bank of Japan raised interest rates.
The move left USD/JPY above Friday’s roughly 156.89 close, according to historical market data. The pair had climbed as high as about 158.05 on Friday, its strongest level in roughly two weeks, immediately after the BOJ decision.
The weakness is notable because the Bank of Japan raised its policy rate by 25 basis points to 1.25% on September 18, its highest level in 31 years. The BOJ’s official policy record confirms the September 18 change, while Reuters reported that the decision passed by a 7-2 vote.
The rate increase itself does not establish why the yen subsequently weakened. Market participants instead focused on how the decision compared with expectations.
Two BOJ members dissented, while Governor Kazuo Ueda kept the possibility of further increases open without committing to a fixed timetable. Reuters cited strategists who said the message was not strong enough to produce a major repricing in the currency.
Intervention Risk Returns
Attention has also shifted back toward Japan’s Ministry of Finance after reports that authorities conducted rate checks following Friday’s sharp currency move. Rate checks do not mean intervention has occurred, but traders often view them as a possible preparatory step.
That matters because Japan and the United States jointly intervened to support the yen in late July after the currency weakened sharply. Finance Minister Satsuki Katayama has since said authorities would not hesitate to take further coordinated action if necessary.
Monday’s conditions added another complication: Japanese markets were closed for a three-day holiday, reducing liquidity and potentially making currency moves larger than they would be during normal trading.
Dollar Pressure Remains
The yen is also trading against a U.S. dollar supported by a higher American rate outlook. The Federal Reserve raised the federal funds target range by 25 basis points to 3.75%–4.00% on September 16, a move Investozora covered in its Fed rate decision report.
The Fed’s official statement confirmed the unanimous increase, while CME-based market pricing cited by Reuters showed traders assigning roughly a 55% probability of another quarter-point increase in October on Monday. That backdrop follows Investozora’s earlier coverage of the U.S. dollar reaching a two-week high as markets reassessed U.S. interest-rate expectations.
For the yen, the immediate question is now whether USD/JPY again approaches Friday’s 158.05 high and whether Japanese authorities respond with additional rate checks, verbal warnings or direct market action.
Traders will also be watching how the currency behaves as normal Japanese market liquidity returns and how expectations develop before the Federal Reserve’s next scheduled meeting on October 27–28.
