The market is pricing in an 84% probability of a rate hike by the Bank of Japan in September.
Participants on the decentralized prediction platform Polymarket have sharply shifted their expectations regarding Japan's monetary policy. In just two weeks, the probability of the Bank of Japan raising its key interest rate at the September meeting has soared from 22% to 84%. This is a signal that cannot be ignored.
Such a rapid reversal in sentiment is linked to the weakening effect of currency interventions by Japanese authorities. The yen, which had previously shown steady gains, is now losing ground and heading toward its most significant weekly decline in three months. This week, the USD/JPY exchange rate fell by approximately 1%, reaching 159.43 yen per dollar—the worst weekly performance since May.
Analyzing the dynamics, I see that the yen has already retraced about half of the gains it made following the coordinated currency intervention by the Bank of Japan in late July and early August. Before those measures, the exchange rate held around 164 yen per dollar. Notably, a similar pattern was observed earlier: after the April intervention, the yen slid back to its multi-year lows over the following months. This confirms that one-off measures without a change in fundamental policy cannot alter the trend.
Traders are betting on tightening
The connection between interventions and key interest rate decisions is becoming increasingly evident. The market now perceives currency interventions not as a standalone tool, but as a prelude to more decisive action by the regulator. In my assessment, market participants are pricing in a quarter-point rate hike with a probability of over 80%, and this aligns with the views of several strategists who believe the yen needs clear support from the Bank of Japan, which is ready to tighten policy.
Such a scenario seems logical, given that inflation in Japan is gradually approaching the target level. However, the opposite scenario carries serious risks. If the regulator leaves the rate unchanged, the market could react with sharp disappointment, and the yen risks falling back to the 160-per-dollar level. Right now, all traders' attention is focused on the central bank's steps, rather than on new interventions, whose effectiveness, as we can see, is limited.
My verdict: The market has effectively cornered the Bank of Japan. Ignoring such expectations would deal a blow to confidence in the regulator and trigger a new wave of yen weakness. A rate hike in September is not just a likely scenario, but perhaps the only way to stabilize the situation without losing face.