The market is pricing in an 84% probability of a rate hike by the Bank of Japan — what is happening with the yen
Participants of the decentralized prediction platform Polymarket estimate the probability of a rate hike by the Bank of Japan in September at 84%. Just two weeks ago, this figure stood at only 22%.
Such a sharp reversal in expectations is linked to changing dynamics in the currency market. The effect of the recent currency intervention by Japanese authorities proved short-lived: the yen has lost a significant portion of its gains and is posting its worst weekly performance in three months.
Intervention No Longer Works
This week, the yen weakened by about 1% to 159.43 per dollar. This is the worst weekly showing since May. The currency has given back about half of the gains that followed the coordinated intervention by the Bank of Japan in late July and early August. Before those measures, the exchange rate was hovering near 164 per dollar.
A similar pattern has been observed before: after the April intervention, the yen returned to multi-year lows over the following months. This confirms that one-off measures without changes in monetary policy are unable to alter the fundamental trend.
Market Bets on Regulator Action
The link between interventions and key rate decisions explains the shift in sentiment. Polymarket players now price in a probability of a quarter-point rate hike above 80%. This consensus aligns with the view of several strategists who believe the yen needs clear support from the Bank of Japan, ready to tighten monetary policy. Inflation in the country is approaching the target level, creating conditions for such a move.
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. Market participants now count on central bank steps rather than new currency interventions, which are increasingly seen as a temporary measure.
My analysis: Current Polymarket quotes reflect not just speculative optimism, but a real shift in market logic. The market is tired of interventions and expects systemic action. If the Bank of Japan meets expectations, the yen could gain sustained support. However, in the event of a pause, we risk seeing a new wave of weakening, which would create additional risks for global markets, including the cryptocurrency one.