Yen at 40-Year Low: BoJ's Countdown Begins

USD/JPY breaks through the 158-160 range - the historic tolerance level of the Ministry of Finance. The Bank of Japan has fewer and fewer reasons not to act in July.

The Fact

The yen hit a 40-year low against the dollar (USD/JPY ~158-160), triggering warning signals at Japan's Ministry of Finance. Simultaneously, the Japanese government included the phrase "appropriate monetary policy" in its draft annual plan—a coded signal of non-opposition to a BoJ hike. In Asia, Tokyo (Nikkei) and Seoul (Kospi) stock exchanges closed mixed at the start of Q3, with the yen as the dominant variable.

Our Take

The BoJ finds itself in a classic bind: raising rates to defend the yen (and contain imported inflation) risks triggering a massive unwinding of the JPY carry trade (positions estimated at several hundred billion dollars). The BoJ's policy rate has been at 0.50% since March 2026—the market priced in a pause, but the yen's extreme weakness changes the calculus.

The dual FOMC (July 29-30) + BoJ (July 30-31) calendar is a rare concentration of systemic risk. If both central banks surprise—the Fed more hawkish and the BoJ more hawkish—the unwinding of the JPY carry trade could trigger a wave of volatility comparable to August 5, 2024.

To Watch

BoJ July 30-31: rates and guidance · MoF: USD/JPY interventions if breaching 160 · JPY carry trade positions (CFTC Commitment of Traders) · FOMC July 29-30.