50% — Bank of Japan Decision in April
Polymarket 47% · Kalshi 70% · 20 contracts · $13K volume · medium confidence
Updated 2026-05-03 16:51:54 UTC

Cross-venue gap: 23pp (Kalshi higher)

Why this matters:
This probability reflects market expectations for a Bank of Japan interest rate decision occurring in April 2026. At 52%, traders are essentially split between two outcomes, suggesting genuine uncertainty about the central bank's monetary policy stance. The probability is primarily driven by recent economic data from Japan—including inflation trends, employment figures, and GDP growth—which determine whether the BoJ will adjust rates or hold steady. Market participants are also factoring in global monetary policy signals, particularly from other major central banks that influence currency valuations and capital flows. The key catalyst for resolving this uncertainty will be the official BoJ decision announcement on its scheduled meeting date, after which the contract will settle based on the actual policy action taken.

Key factors:
- Recent Japan CPI and core inflation readings relative to BoJ's 2% target, which directly influences rate decision likelihood
- Employment and wage growth data showing labor market tightness, a key factor in the BoJ's policy calculus
- USD/JPY exchange rate movements and expectations for Fed policy divergence, which affect BoJ decision timing
- Scheduled BoJ Monetary Policy Decision meeting date and any forward guidance statements released beforehand
- Comparative rate expectations across other G7 central banks, which shape relative attractiveness of yen-denominated assets

Contracts:
- Reserve Bank of Australia Decision in May?: No Change — 5¢ Polymarket $4K (weight 8%)
- Reserve Bank of Australia Decision in May?: Increase — 95¢ Polymarket $3K (weight 8%)
- Bank of Russia decision in June?: Decrease — 79¢ Polymarket $2K (weight 7%)
- Bank of Mexico Decision in May: Decrease — 93¢ Polymarket $927 (weight 7%)
- Bank of Mexico Decision in May: No change — 6¢ Polymarket $744 (weight 6%)
- Bank of Brazil Decision in June?: No Change — 22¢ Polymarket $360 (weight 6%)
- Bank of Japan Decision in June?: 25 bps increase — 51¢ Polymarket $301 (weight 6%)
- Bank of Korea decision in May?: No Change — 95¢ Polymarket $263 (weight 5%)
- ... and 12 more

Cite as: "50% per prediction markets (SimpleFunctions, May 2026)"
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