Japan’s monetary base remained in sharp decline in September 2026, though the pace of contraction eased marginally compared with the previous month, according to data updated on 1 October 2026. The monetary base fell 15.2% year-over-year in September, improving slightly from a 15.7% year-on-year drop recorded in August 2026.
The figures are calculated on a year-over-year basis, comparing each month to the same month a year earlier. While the less severe contraction in September suggests some stabilization in the pace of monetary tightening or liquidity withdrawal, the data still point to a significantly smaller central bank balance sheet compared with a year ago. Investors and analysts will be watching upcoming releases closely to gauge whether this moderation continues and what it may signal for Japan’s broader monetary and financial conditions.
