The market is pricing in an 84% probability of a rate hike by the Bank of Japan in September.
Data from the decentralized prediction platform Polymarket points to a dramatic shift in market participants' 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 surged from 22% to 84%. This is a signal that no trader working with Asian currencies can afford to ignore.
Failed interventions: the yen under pressure again
The reason for such a sharp revision of expectations is the weakening effect of currency interventions by Japanese authorities. The yen has lost roughly half of the gains achieved after coordinated actions by the Bank of Japan and the Ministry of Finance in late July and early August. At that time, the exchange rate pulled back from the 164-per-dollar mark, but now it is once again showing a downward trend, posting its worst weekly performance in three months.
This week, the Japanese currency weakened by about 1%, reaching 159.43 per dollar. This is a repeat of the April scenario, when the yen returned to multi-year lows within months after an intervention. The market is beginning to understand: one-off measures do not solve structural problems.
Market view: central bank action needed
Significantly, Tokyo's former top currency diplomat Mitsuhiro Furusawa indicated in his comments that authorities are ready to deploy currency reserves at any moment. However, he also stressed that a faster pace of rate hikes could be a more effective tool for supporting the currency. This logic resonates with market participants.
OCBC strategists note that interventions alone are insufficient to reverse the yen's dynamics. "Unsurprisingly, the yen has given up ground again," the analysts state. In their assessment, the currency needs clear support from the Bank of Japan, which is ready to tighten monetary policy. Given that inflation is approaching the target level, the arguments in favor of a rate hike are becoming increasingly compelling.
Risks of the opposite scenario
However, it is worth remembering the opposite scenario. If the regulator leaves the rate unchanged, the market could react with disappointment, and the yen risks falling back to the 160-per-dollar level. Currently, market participants are betting on central bank action rather than new currency interventions, which underscores the high degree of expectation concentration around the September meeting.
My view: the sharp jump in probability on Polymarket reflects not so much confidence in the Bank of Japan's actions as market fatigue with ineffective interventions. If the regulator meets expectations, the yen could receive short-term support. But in the long term, without sustained policy tightening, pressure on the currency will persist, and this will be an important factor for anyone holding positions in Japanese assets.