The market is pricing in an 84% probability of a rate hike by the Bank of Japan in September.
The decentralized prediction market Polymarket is showing a sharp reversal in expectations regarding Japan's monetary policy. Platform participants now estimate the probability of a rate hike by the Bank of Japan at its September meeting at 84%. For comparison, just two weeks ago, this figure stood at only 22%.
This rapid shift in consensus is linked to the weakening effect of currency interventions by Japanese authorities. The yen has lost a significant portion of its recent gains and is heading toward its strongest weekly decline in three months.
The intervention effect is fading
This week, the Japanese currency has fallen by about 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 all 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 was holding around 164 yen per dollar.
Similar dynamics were observed earlier: after the April intervention, the yen returned to a 40-year low in the following months. This confirms that one-off targeted interventions without changes to the fundamental parameters of monetary policy cannot provide sustained support for the national currency.
Significantly, Tokyo's former top currency diplomat Mitsuhiro Furusawa does not rule out new interventions, but, according to him, authorities are also ready to signal to the market the possibility of a faster rate hike to support the currency.
Traders bet on a rate hike
The connection between interventions and key rate decisions explains the shift in market expectations. Polymarket participants now price in a probability of a quarter-point rate hike above 80%. OCBC strategist Sim Moh Siong rightly notes that interventions alone will not reverse the dynamics of the Japanese currency.
"It is not surprising that the yen has given up ground again," the analyst states.
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 approaches the target level.
The opposite scenario carries risks: if the regulator leaves the rate unchanged, the market will quickly react with disappointment. After such decisions, the yen has already fallen to 160 per dollar. Currently, market participants are counting on central bank steps rather than new currency interventions.
My comment: The sharp jump in probability on Polymarket reflects not just speculative sentiment but a fundamental market understanding: without real policy tightening, the yen is doomed to further weakening. For the crypto market, this is an important signal — yen strengthening and normalization of BOJ policy could reduce the attractiveness of carry-trade strategies, which may impact global liquidity and, consequently, risk assets, including digital currencies.