The Bank of Japan is set to raise its policy interest rate to 1.25% on September 18, marking the highest level in about 31 years as policymakers respond to persistent inflation and renewed pressure on the yen. The expected increase represents another step away from Japan’s decades-long era of ultra-low interest rates and comes at a sensitive moment for global markets following the Federal Reserve’s latest rate decision and continued energy-market volatility.

Inflation and Energy Costs Strengthen the Case for Higher Rates

The BOJ is confronting a combination of domestic and imported price pressures. Japan’s core consumer inflation held at 1.7% year over year in August, remaining close to the central bank’s 2% target, while higher oil prices have raised costs for households and businesses. A weaker yen has added to the pressure by making imported energy, food and other goods more expensive.

The expected move to 1.25% would be the BOJ’s first rate increase in three months. Policymakers are seeking to move rates gradually closer to what they view as a more neutral level while avoiding unnecessary damage to domestic demand. The challenge is balancing inflation risks against the impact of higher borrowing costs on consumers, companies and investment.

The Yen Remains Central to the BOJ’s Decision

The yen has become one of the most important considerations for Japanese policymakers. The currency recently traded around ¥156 per dollar after weakening from a seven-month high near ¥152.89 earlier in the month. The move reflects the continuing gap between Japanese and U.S. interest rates, particularly after the Federal Reserve raised its policy rate to 3.75%–4.00% and signaled a more restrictive stance.

A BOJ rate increase could provide some support for the yen, but the currency’s reaction will depend heavily on expectations for future policy. If Governor Ueda signals that additional hikes are likely, Japanese yields could rise further and encourage a stronger yen. A cautious message, however, could limit the impact of the immediate rate increase.

Ueda’s Guidance May Matter More Than the Initial Hike

Because a 25-basis-point increase is already widely anticipated, investors are likely to focus more closely on the BOJ’s forward guidance. Markets are watching whether policymakers see inflation as sufficiently persistent to justify another increase later in the year and how the central bank assesses the economic impact of higher oil prices and geopolitical uncertainty.

The policy outlook also matters beyond Japan. Higher Japanese interest rates can influence the carry trade, global bond yields and capital allocation because Japanese investors hold substantial amounts of overseas assets. A faster tightening cycle could encourage some of that capital to return to Japan, while a slower path could preserve demand for higher-yielding assets abroad.

The September decision therefore represents more than another quarter-point adjustment. The immediate focus will be the move to 1.25%, but the larger market question is whether the BOJ is preparing for a sustained normalization cycle. Inflation, energy prices, wages, the yen and domestic demand will remain the key variables shaping future decisions and their impact on global financial markets.