How to read the data: the per-auction amount and the monthly amount are different numbersHow much per auction and how much per month are different numbers
On October 30, the Bank of Japan published the updated version of its quarterly schedule of outright purchases of Japanese government bonds by competitive auction for October to December 2026. For each residual maturity band the table shows two amounts, the purchase size per auction and the monthly purchase size, where the monthly figure is the per-auction amount multiplied by the number of auctions in that month. Here is how to read the table, and what the notes say, so that you can tell which of the two a headline figure refers to.
Key points
- The residual maturity bands are up to 1 year, over 1 and up to 3 years, over 3 and up to 5 years, over 5 and up to 10 years, over 10 and up to 25 years, over 25 years, and inflation-indexed bonds
- Purchase size per auction is JPY 100 billion for up to 1 year, JPY 330 billion for over 1 and up to 3 years, JPY 290 billion for over 3 and up to 5 years, JPY 305 billion for over 5 and up to 10 years, JPY 85 billion for over 10 and up to 25 years, JPY 75 billion for over 25 years, and JPY 30 billion for inflation-indexed bonds
- Monthly purchase size is JPY 100 billion for up to 1 year, JPY 660 billion for over 1 and up to 3 years, JPY 580 billion for over 3 and up to 5 years, JPY 610 billion for over 5 and up to 10 years, JPY 170 billion for over 10 and up to 25 years, JPY 150 billion for over 25 years, and JPY 30 billion for inflation-indexed bonds, totaling JPY 2.3 trillion
- The published material notes that purchase sizes are approximate, and that the Bank may change the frequency as needed, taking account of market conditions
- The schedule for December 2026 is due at 5 p.m. on November 30, 2026, and the quarterly schedule for January to March 2027 at 5 p.m. on December 25, 2026
What to do in practice
- When you see a figure for how much the Bank buys in a month, check that it is the per-auction amount multiplied by the number of auctions, and that the frequency can change
The Bank of Japan buys government bonds, the certificates the state issues when it borrows money, from banks and other institutions. The schedule published on October 30 shows two figures side by side: how much it buys in one auction, and how much it buys in a month. The monthly figure is the per-auction amount multiplied by the number of auctions that month. For example, JPY 330 billion per auction twice a month comes to JPY 660 billion for the month. The schedule also says the number of auctions may change depending on conditions.
- Per auction
- JPY 330 billion
- x auctions in the month
- 2
- Monthly purchase size
- JPY 660 billion
Points
- The schedule shows two figures: how much per auction, and how much per month
- The monthly figure is an approximation, the per-auction amount multiplied by the number of auctions
- The notes say the number of auctions may change depending on conditions
What the words mean
- Government bond
- A certificate the state issues when it borrows money
- Purchase size
- The amount the Bank of Japan indicates it will buy
- Bank of Japan (BOJ): Bank of Japan: Quarterly Schedule of Outright Purchases of Japanese Government Bonds (Competitive Auction Method), October-December 2026, schedule updates
Economic news presents published statistics and outlooks. It is not investment solicitation or trading advice. Figures are as of publication and may be revised.
This article summarizes and explains materials published by government agencies and is not advice on any individual case. Rules can change, so for actual procedures and decisions always check the latest original materials and consult professionals such as tax accountants or labor and social security attorneys. English, Simplified Chinese and Traditional Chinese versions are translations prepared from the Japanese articles for convenience. If anything differs, the Japanese text and the original source take precedence.