Yen breaks 155 as BOJ consecutive-hike signal fuels rally

The yen climbed to its strongest since February, breaking through 155 per dollar to 154.06 in London trading, as Bank of Japan board member Hajime Takata's consecutive-hike signal intensified expectations for faster tightening at the September 18 meeting.

"This feels like the beginning of a larger move," said Van Luu, global head of fixed income and FX solutions strategy at Russell Investments. "The first intervention's effect has faded, and this second wave appears driven by more factors."

The yen gained 2.4 percent last week and rose another 1.4 percent Monday. The break below 155 triggered a cascade of stop-loss orders and forced options marketmakers to sell dollars, accelerating the move. Japan's foreign reserves fell $94.6 billion to $995 billion in August after authorities deployed about ¥15.4 trillion ($98.6 billion) for intervention, with the reduction largely funded by selling U.S. Treasuries.

The September 18 BOJ decision now carries outsized weight. Overnight index swaps have already priced in a quarter-point hike from the current 1 percent policy rate, meaning the surprise would be a hold. If Governor Kazuo Ueda indicates that September is part of a faster tightening sequence, the yen could extend gains toward 152, the next technical support identified by Motonari Sakai, chief manager of FX and financial products trading at MUFG Trust Bank.

Takata's Consecutive-Hike Signal Reshapes Rate Expectations

Takata's comments last week marked a notable shift in BOJ communication. He said future rate increases would not be rigidly limited to 25-basis-point increments and that consecutive hikes were possible under normal circumstances. The remarks came just three months after the BOJ's 25-basis-point increase in June, which would make a September move the fastest tightening pace under Ueda's governorship.

The hawkish stance has also drawn attention from Washington. Treasury Secretary Scott Bessent has repeatedly emphasized the importance of tighter Japanese monetary policy, and the United States joined Japan in buying yen on July 31 — the first coordinated intervention since 1998. Japan's top FX official, Jun Mimura, said his "combat stance" on the yen remains unchanged.

Structural Yen Demand Builds Beyond the Technical Break

Multiple factors beyond the 155 breakdown are supporting the yen. Speculation that the Government Pension Investment Fund may adjust its asset allocation has added structural yen demand, while month-start seasonal rebalancing by real-money portfolios has provided additional flows. Falling oil prices have also improved Japan's terms of trade, giving the currency a fundamental tailwind.

Options market signals confirm the shift. Implied volatility covering the next BOJ and Federal Reserve policy meetings rose to its highest level since January, while the premium for options hedging against yen appreciation approached cycle highs. Masahiko Loo, senior fixed income strategist at State Street Investment Management, noted that 155 had served as significant support following several rounds of intervention, making its loss technically meaningful.

The yen's longer-term direction depends on whether markets begin pricing a credible sequence of hikes rather than a single move. Japanese rates remain well below U.S. levels, and the yield differential continues to incentivize carry trades. A September hike followed by another long pause could leave the currency vulnerable, while a signal of accelerated tightening could begin changing capital flows more fundamentally.

Prime Minister Sanae Takaichi's historically accommodative stance on monetary policy adds a political constraint. Japan's public debt load makes the economy particularly sensitive to sustained increases in government bond yields, limiting how aggressively the BOJ can raise rates without destabilizing growth.

This article is for informational purposes only and does not constitute investment advice.