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 revised their expectations regarding Japan's monetary policy. The probability of a rate hike by the Bank of Japan at the September meeting is now estimated at 84%. Just two weeks ago, this figure stood at only 22%.
This rapid shift in market sentiment is a direct consequence of the weakening effect of currency interventions by Japanese authorities. The yen, which had previously shown steady gains, is now losing its acquired positions, and the market increasingly doubts the effectiveness of one-off support measures.
The yen loses ground
This week, the Japanese currency declined by approximately 1%, reaching 159.43 yen per dollar. This is the worst weekly result since May. Notably, the yen has already given back about half of the gains it made following the coordinated currency intervention by the Bank of Japan in late July and early August. Before these measures, the exchange rate held around 164 yen per dollar.
Similar dynamics were observed earlier. After the April intervention, the yen retreated to lows again in the following months, updating multi-year levels. This confirms that targeted currency interventions without changes to fundamental monetary policy provide only a temporary effect.
Former top Tokyo currency diplomat Mitsuhiro Furusawa noted in one of his comments that authorities could tap currency reserves again at any moment. However, according to him, officials are also ready to signal the market about a faster rate hike to support the national currency. It is this signal that the market is currently trying to read.
Betting on the central bank's resolve
The connection between interventions and key rate decisions is becoming increasingly evident. Polymarket participants now estimate the probability of a quarter-point rate hike at over 80%, reflecting a shift in expectations.
OCBC strategist Sim Moh Siong believes that interventions alone will not reverse the dynamics of the Japanese currency. "It's no surprise that the yen has given up ground again," he stated. In his assessment, the yen needs clear support from the Bank of Japan, which is ready to tighten monetary policy. This view aligns with growing expectations of a faster rate hike, as inflation gradually approaches the target level.
The opposite scenario carries serious risks. If the regulator leaves the rate unchanged, the market could quickly react with disappointment—in such a case, the yen has already fallen to 160 per dollar. Currently, market participants are betting on the central bank's steps rather than on new currency interventions.
My analysis: The current dynamics of the yen are a classic example of how the market tests the regulator's resolve. One-off interventions without changes to interest rate policy are perceived as a temporary measure, and traders understand this perfectly well. If the Bank of Japan fails to meet expectations in September, we could see a sharp acceleration in the yen's weakening, which would put pressure not only on Japanese assets but also on global markets, including the cryptocurrency sector, which is sensitive to changes in liquidity.