Bank of Japan September 2026 Meeting
The official two-day schedule, verified rate-market structure, settlement rules, and research checkpoints before the September decision.
Published July 29, 2026 · Substantially updated August 2, 2026 · Meeting: September 17–18, 2026 · Next planned refresh: August 24, 2026
The answer first
The Bank of Japan's September 2026 Monetary Policy Meeting is scheduled for Thursday and Friday, September 17–18. On July 31, the Policy Board voted 8–1 to keep the guideline for the uncollateralized overnight call rate at around 1.0%; Hajime Takata proposed 1.25%, but that proposal was defeated. An exact Polymarket event for the September decision remained active and open in the August 2 research check, with five possible change buckets: a decrease of at least 50 basis points, a 25-basis-point decrease, no change, a 25-basis-point increase, or an increase of at least 50 basis points. The September outcome is unknown. This guide does not freeze a fast-moving price or forecast the decision; it maps the new official baseline, dates, measured rate, and edge-case rules that control resolution.
What changed after the July 31 BOJ decision
The 1.0% guideline stayed in place
The Bank had raised the uncollateralized overnight call rate guideline to around 1.0% on June 16, effective June 17. Its July 31 statement set the same guideline for the next intermeeting period, giving this page a verified post-July policy baseline.
The vote exposed an upside dissent
The July decision passed 8–1. Hajime Takata argued for a guideline around 1.25%, citing upside price risks from overseas demand shocks and financial conditions. The proposal was defeated; it is evidence about the vote, not proof of what September will deliver.
September still uses a fresh comparison
The reviewed contract does not permanently compare September with July 31. It compares the specified rate immediately before the September meeting with the change resulting from that meeting, so any intervening qualifying action must be documented separately.
Official Bank of Japan September 2026 timeline
The Policy Board voted 7–1 to encourage the uncollateralized overnight call rate to remain at around 1.0%, effective June 17. That June change explains why the identical figure in the July statement represented continuity rather than a new increase.
The July 31 statement kept the guideline around 1.0% by an 8–1 vote. Hajime Takata preferred 1.25%. The official calendar also links an Outlook Report to this meeting, establishing the latest completed decision before September.
The exact September event and all five component markets were active, not closed, and accepting orders at 14:05 UTC. The event showed about $167,973 in cumulative volume and $45,679 in liquidity at that timestamp; live values will change, so no outcome prices are preserved here.
The official calendar schedules this release for 8:50 a.m. It can add detail about the range of Policy Board views after the 8–1 decision, but it does not replace the later September statement as the named settlement evidence for the reviewed event.
The guide will recheck the post-July evidence, September dates, all five market descriptions, active status, source hierarchy, and any rule changes. A material update triggers an earlier review.
Inflation, wages, activity, financial conditions, official speeches, and the July Summary of Opinions can change expectations before the next meeting. Those inputs may move forecasts and order books, but none substitutes for the official September decision as the reviewed event's named settlement evidence.
The Bank of Japan schedules this meeting across Thursday and Friday. The reviewed prediction-market rules compare the specified overnight rate immediately before the meeting with the change resulting from this meeting.
The official calendar schedules this later release for 8:50 a.m. The market may already resolve from the September policy statement, so the Summary of Opinions is a useful research document rather than a reason to assume settlement must wait.
This next meeting matters to the postponement clause. If the September meeting is cancelled, or delayed so no decision arrives before the next scheduled meeting begins, the reviewed rules assign the no-change bucket.
What the verified September Polymarket event covers
The exact event reviewed for this guide is titled Bank of Japan Decision in September? At 14:05 UTC on August 2, its top-level event was active and not closed. All five component questions were active, not closed, and accepting orders. Cumulative event volume was about $167,973 and displayed liquidity about $45,679 at that timestamp, up from the July 29 research baseline; both will change. The useful durable structure is the set of resolution buckets:
50+ bps decrease
A decrease that the event classifies in its 50-basis-point-or-larger bucket after applying the written rounding method.
25 bps decrease
A smaller qualifying decrease classified as 25 basis points. One basis point is 0.01 percentage point, so 25 basis points equals 0.25 percentage point.
No change
No qualifying change in the specified rate resulting from the September meeting, including the cancellation or long-postponement fallback in the reviewed rules.
25 bps increase
A qualifying increase classified as 25 basis points under the same meeting boundary and rounding method.
50+ bps increase
An increase placed in the 50-basis-point-or-larger bucket after the contract's classification rules are applied.
Five binaries, one decision
Each outcome is a separate yes/no order book. Displayed YES prices may not add to exactly 100% because spreads, depth, timing, and independent orders can differ.
This event is narrower than a general question about Japanese interest rates or where policy will finish in 2026. It names one two-day meeting, one overnight rate, one before-and-after comparison, and one official source hierarchy. That distinction prevents similar-looking central-bank markets from being treated as interchangeable.
Bank of Japan market resolution: eight rules that matter
1. One rate is specified
The event measures the change in the uncollateralized overnight call rate. Broader commentary about yields, inflation, bond purchases, or the yen does not by itself answer that precise contract question.
2. Compare immediately before and after
Resolution uses the change resulting from the September meeting relative to the specified rate's level before that meeting. A level observed weeks earlier is context, not a fixed settlement baseline.
3. Use the upper bound if needed
The rules say that if the specified rate is defined by upper and lower bounds, the relevant change is the change to the upper bound. That clause supplies one consistent comparison if a range is used.
4. Small nonzero moves round to 25
An increase or decrease smaller than 25 basis points is treated as a 25-basis-point move. Under the reviewed wording, a 10-basis-point change would not become “no change.”
5. Larger moves use nearest-25 rounding
Changes greater than 25 basis points are rounded to the nearest 25. An exact tie is rounded away from zero, so a 37.5-basis-point move is classified as 50 basis points.
6. Official information controls
The event names official Bank of Japan information, including the statement or release from the September meeting. Surveys, news reports, analyst calls, and market prices can inform expectations but are not the named resolution source.
7. Emergency changes are excluded
An emergency change that does not result from the specified meeting does not count under the reviewed rules. This is a meeting-specific event, not a contract on any policy action before September 18.
8. Schedule fallbacks are explicit
A postponed meeting counts if it occurs before the next scheduled MPM. Cancellation, or a delay past the start of that next meeting, resolves to no change under the wording checked for this guide.
A reproducible note should preserve the exact event slug, all five question labels, complete description, source link, active/closed status, and check time. A screenshot of one price does not preserve the rate definition, rounding method, or schedule fallbacks.
Why search demand should rise before September 17
This substantial update lands 46 days before the scheduled meeting begins, leaving time for search engines to recrawl a stable canonical before date, outcome, and resolution intent becomes concentrated. The topic was not selected only because the July decision was recent: the September meeting is independently scheduled on the Bank's annual calendar, and a dedicated five-outcome event remains active.
Post-July baseline wave
With the 1.0% guideline and 8–1 vote now official, users can shift from “what did the BOJ do?” toward “when is the next Bank of Japan meeting?” and “will the BOJ change rates in September?” This update preserves one canonical for that next-meeting intent.
Late-summer evidence wave
As official economic evidence and policy communication arrive, attention can move from the calendar toward the five rate buckets and the Policy Board's reaction function. This guide keeps settlement mechanics separate from any changing forecast.
Decision-week wave
Intent should become most specific around the official announcement, current market status, source hierarchy, and settlement evidence. A final pre-meeting review will remove stale status language; a post-event update can preserve the confirmed result.
Research workflow for the September BOJ decision
Start with the official calendar
Verify September 17–18 on the Bank of Japan site. Do not infer the meeting date from a market end time, an unofficial economic calendar, or a social post.
Refresh the policy baseline
Use the July 31 statement to record the current guideline around 1.0% and the 8–1 vote. Keep that level distinct from a forecast, from the rate immediately before September, and from the later change caused by the September meeting.
Read all five questions
Confirm that every outcome carries the same meeting, rate, source, rounding, postponement, and emergency-action wording. One abbreviated outcome label cannot describe the complete event.
Measure the order books
Use the prediction-market odds guide to record spread and depth instead of treating the last trade as an exact probability. Separate binaries can contain apparent gaps.
Compare institutions carefully
The September ECB, September Fed, and September Bank of England guides cover different dates, policy rates, committees, and contract language. One decision does not mechanically determine another.
Separate context from settlement
The U.S. CPI calendar and U.S. jobs calendar help map the global macro attention cycle, but neither is the BOJ event's named resolution source.
Investigate sudden moves
The biggest-movers watchlist can flag a contract for review. It cannot establish whether a move reflects new evidence, thin liquidity, or one order.
Keep probability claims bounded
The prediction-market accuracy guide explains why a quoted probability is evidence to assess, not certainty. No outcome or return is guaranteed.
Frequently asked questions
When is the September 2026 Bank of Japan meeting?
The official Bank of Japan calendar schedules the Monetary Policy Meeting for Thursday and Friday, September 17–18, 2026. The decision is normally announced immediately after the meeting.
What did the Bank of Japan decide on July 31, 2026?
The Policy Board voted 8–1 to keep the guideline for the uncollateralized overnight call rate at around 1.0%. Hajime Takata proposed 1.25%, but that proposal was defeated. This official baseline is context for September, not a forecast of the next decision.
Are there active Bank of Japan September 2026 prediction markets?
Yes. The exact Polymarket event checked August 2, 2026 at 14:05 UTC was active and open with five rate-change outcome contracts: 50+ basis-point decrease, 25-basis-point decrease, no change, 25-basis-point increase, and 50+ basis-point increase.
Which rate resolves the September Bank of Japan market?
The reviewed event measures the change in the uncollateralized overnight call rate resulting from the specified September meeting, relative to its level immediately before that meeting. Official Bank of Japan information is the named resolution source.
How are unusual Bank of Japan rate changes classified?
The reviewed rules treat a nonzero change smaller than 25 basis points as a 25-basis-point move. Larger changes are rounded to the nearest 25 basis points, with an exact tie rounded away from zero.
Do emergency Bank of Japan rate changes count?
Not under the reviewed wording if the emergency change does not result from the specified September meeting. The event is meeting-specific rather than a general bet on any rate move before September 18.
When will this Bank of Japan September 2026 guide be refreshed?
The next planned refresh is August 24, 2026, after the July Summary of Opinions and before the September meeting. An earlier review will follow any material change to the official calendar, market status, policy baseline, or written rules.
Sources and methodology
- Bank of Japan: Monetary Policy Meetings — official July 30–31, September 17–18, and October 29–30 meeting dates plus the August 10, October 1, and November 5 release schedule. Checked August 2, 2026 at 14:04 UTC.
- Bank of Japan: June 16 Change in the Guideline for Money Market Operations — official 7–1 decision to move the uncollateralized overnight call rate guideline to around 1.0%, effective June 17. Checked August 2, 2026.
- Bank of Japan: July 31 Statement on Monetary Policy — official 8–1 decision to keep the guideline around 1.0% and the defeated 1.25% proposal. Checked August 2, 2026.
- Bank of Japan: Outline of Monetary Policy — official explanation of the Policy Board, two-day MPM process, money-market-operation guidelines, and immediate decision announcements. Rechecked August 2, 2026.
- Polymarket Gamma: Bank of Japan Decision in September? — exact event status, five open markets, specified overnight rate, official source hierarchy, rounding, emergency-action, postponement, and cancellation rules. Checked August 2, 2026 at 14:05 UTC.
- Public Polymarket event — live surface for current order books and contract text. Prices are intentionally not reproduced here.
Candidate and cannibalization review covered the complete 98-entry blog index and article archive, all 18 event hubs, the 125-URL sitemap, proactive state and refresh queue, current-day publisher output, and the latest local GSC snapshot and watchlist. Exact and semantic scans confirmed that this canonical already owns the Bank of Japan September meeting intent, so it was substantially expanded instead of creating a competing article. The nearest pages cover the Federal Reserve, European Central Bank, Bank of England, and Bank of Canada; each uses a different institution, calendar, policy rate, event ID, and primary keyword.