Bank of Japan September 2026 Decision: Hiked 25 bp to 1.25%
The settled September 18, 2026 decision record: the official statement outcome, the market’s resolution, the complete timeline, resolution rules, and FAQs.
Published July 29, 2026 · Substantially updated September 18, 2026 (post-decision settlement record) · Meeting: September 17–18, 2026 · Decision: 25 bp hike to 1.25%, September 18 · Next planned refresh: settlement confirmation check, ~September 24
The answer first
The Bank of Japan raised its policy rate by 25 basis points to around 1.25 percent at the close of its September 17–18, 2026 meeting — the statement went out Friday, September 18 with a 7–2 vote, moving the guideline for the uncollateralized overnight call rate up from around 1.0 percent effective September 24, 2026, alongside a complementary deposit facility rate of 1.25 percent and a basic loan rate of 1.5 percent. The two dissenters — Asada Toichiro and Sato Ayano — argued for holding the previous guideline, a mirror image of July’s defeated proposal for exactly the 1.25% level that has now become policy. Polymarket’s Bank of Japan Decision in September? event then settled the way its rules name: the 25-basis-point increase bucket resolved to Yes at $1.00, the other four buckets closed at zero, and the event finished with roughly $1.52 million in cumulative volume — up from $762,690 at the September 13 final pre-meeting check, when the board priced the hike at 98.45¢. The Bank said it “will continue to raise the policy interest rate and adjust the degree of monetary accommodation,” and the next scheduled meeting is October 29–30; its live event showed a displayed 82¢ no-change against 13¢ for another 25-basis-point increase at the September 18 snapshot. This page now records the settled outcome, the market’s resolution record, and the rulebook that governed them.
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.
What changed in the August 26 refresh
The July Summary of Opinions was released
Published August 10 at 8:50 a.m. JST as scheduled, it shows a Board balancing patience with further tightening: some members stressed the roughly one-to-one-and-a-half-year lag before a hike’s effects fully emerge, while others argued for continuing to raise the policy rate, including one view that the pace could exceed market expectations. Several opinions flagged price risks skewed to the upside and underlying inflation reaching the 2 percent target between the second half of fiscal 2026 and fiscal 2027.
Event volume has more than doubled
Cumulative event volume grew from about $167,973 on August 2 to about $347,340 on August 26 at 14:03 UTC, with displayed liquidity near $55,228 and roughly $1,364 traded in the prior 24 hours. Higher volume signals attention, not a settlement outcome.
Rules and dates re-verified unchanged
The official calendar still lists the meeting for September 17–18, the Summary of Opinions for October 1, and the minutes for November 5. The live contract text was rechecked for the overnight call rate definition, official-source hierarchy, 25-basis-point rounding, emergency-action exclusion, and postponement fallbacks; nothing changed.
A timestamped snapshot was added
This refresh preserves the full five-bucket snapshot below for the first time, with the exact UTC timestamp, so later reviews can document how the board repriced between the July baseline and the meeting. A snapshot is a research artifact, not a forecast.
What changed in the September 13 final pre-meeting refresh
The board repriced toward a September hike
Between the August 26 snapshot (14:03 UTC) and the September 13 recheck (14:03 UTC), the 25-basis-point increase contract moved from a displayed 86¢ to 98.45¢ (bid 98.3¢ / ask 98.6¢), while no change slipped from 13¢ to 1.2¢. The guide records the move as a timestamped fact about order books, not as a forecast—the outcome remains unset until the official September statement. The same late-summer window also repriced the September Fed decision board, which documents its own shift from a near coin flip to hike-favored; one central bank's repricing does not mechanically determine another's.
Volume more than doubled again
Cumulative event volume grew from about $347,340 on August 26 to about $762,690 on September 13, with $115,119 traded in the prior week and $4,292 in the prior 24 hours. Rising volume measures attention into decision week, not a settlement result.
Official schedule re-verified unchanged
The Bank's calendar still lists the Monetary Policy Meeting for September 17–18, the Summary of Opinions for October 1, the minutes for November 5, and the next MPM for October 29–30. The reviewed contract text—rate definition, official-source hierarchy, rounding, emergency-action exclusion, postponement fallbacks—rechecked unchanged.
Official communication continued
The Bank's official speeches page lists two scheduled "Economic Activity, Prices, and Monetary Policy in Japan" speeches with local leaders between checks—September 2 in Sapporo and September 10 in Fukui. Speeches inform expectations, but none replaces the September statement as the event's named resolution source.
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 release arrived on schedule at 8:50 a.m. JST. It documents a range of Board views after the 8–1 decision—patience given the policy transmission lag, calls to keep adjusting the degree of accommodation, and upside-skewed price risks—but it does not replace the later September statement as the named settlement evidence for the reviewed event.
This update rechecked the post-July evidence, September dates, all five market descriptions, active status, source hierarchy, and rule text against the live event, and added the timestamped August 26 snapshot. A material change still triggers an earlier review.
Three days before the meeting begins, this update re-verified the calendar, rebased the five-bucket snapshot onto the 14:03 UTC board, documented the 86¢→98.45¢ repricing of the 25-basis-point increase contract, and cleared stale status language for decision-week readers.
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 Policy Board raised the guideline for the uncollateralized overnight call rate from around 1.0% to around 1.25% by a 7–2 vote, announced with the statement released Friday, September 18, 2026, and effective September 24. The reviewed rules compared the specified overnight rate immediately before the meeting with the change resulting from this meeting — a 25-basis-point increase that resolved the +25 bps bucket to Yes.
The official calendar schedules this later release for 8:50 a.m. The market has already resolved from the September 18 policy statement; the Summary of Opinions adds the Board’s argumentation record — including the two dissents — for readers reconstructing the decision.
This is where dated attention rotates next: the live October event showed a displayed 82¢ no-change against 13¢ for another 25-basis-point increase at the September 18 snapshot (about $118,078 volume, $78,085 liquidity, $10,397 traded in 24 hours) after the September decision reset the baseline to 1.25% effective September 24. The dedicated October 29–30 Bank of Japan guide tracks that next meeting.
Settled: how the September market resolved
The exact Gamma event Bank of Japan Decision in September? was rechecked on September 18, 2026 at 14:03 UTC, the day of the decision. It is closed: all five component contracts stopped trading, the event finished with approximately $1.52 million in cumulative volume ($547,879 on the winning 25-basis-point increase contract, $502,999 on the 50+ basis-point increase, $392,105 on no change, $48,009 on the 25-basis-point decrease, and $33,654 on the 50+ basis-point decrease), and the 25-basis-point increase bucket resolved to Yes at $1.00 while the other four closed at $0. The settlement matches the named resolution source — the September 18 Bank of Japan statement — exactly as the rules required: the specified overnight call rate moved from around 1.0 percent immediately before the meeting to around 1.25 percent as a result of it, a change the written rounding rules classify as a 25-basis-point increase. That final volume is roughly double the $762,690 recorded at the September 13 pre-decision check and confirms this canonical page as the September record; the dated October 29–30 intent belongs to the October 2026 Bank of Japan meeting guide. 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.
| Outcome | Settled | Final contract volume |
|---|---|---|
| 50+ bp decrease | No ($0) | $33,654 |
| 25 bp decrease | No ($0) | $48,009 |
| No change | No ($0) | $392,105 |
| 25 bp increase | Yes ($1.00) | $547,879 |
| 50+ bp increase | No ($0) | $502,999 |
Historical: September 13 snapshot (14:03 UTC)
$762,690
cumulative event volume at the snapshot timestamp, up from about $347,340 on August 26 and about $167,973 on August 2.
$57,791
displayed liquidity across the five order books at the same timestamp.
$4,292
traded in the 24 hours before the snapshot, within $115,119 traded over the prior week.
| Bucket | YES | Bid / Ask | Contract volume |
|---|---|---|---|
| +25 bps | 98.45¢ | 98.3¢ / 98.6¢ | $273,229 |
| No change | 1.2¢ | 1.1¢ / 1.3¢ | $230,143 |
| +50+ bps | 0.5¢ | 0.4¢ / 0.6¢ | $195,488 |
| −25 bps | 0.1¢ | — / 0.2¢ | $38,934 |
| −50+ bps | 0.05¢ | — / 0.1¢ | $24,896 |
The settlement table above is a recorded fact about a finished market. The September 13 table below preserves the final pre-decision board as the historical observation: displayed YES prices summed to about 100.30% because five independent order books carry their own spreads and depth, volume measures attention rather than probability, and a 98.45¢ favorite — the strongest possible read short of certainty — still settled through the same written rulebook as every other bucket. Anyone researching a live board should open the source event, record bid and ask rather than only the last trade, and timestamp the observation.
What changed since the September 13 snapshot
The hike arrived 7–2, with new dovish dissents
The Policy Board raised the guideline for the uncollateralized overnight call rate to around 1.25%, effective September 24, 2026. Asada Toichiro and Sato Ayano dissented, arguing that economic and price developments did not justify raising the policy rate yet — the reverse of July, when Takata’s proposal for exactly the 1.25% level was defeated 8–1. The level that lost in July became policy in September.
The market settled to the statement
The 25-basis-point increase bucket resolved to Yes at $1.00, and the event closed with about $1.52 million in cumulative volume, up from $762,690 at the September 13 check. About $468,000 traded in the final 24 hours alone — more than the whole event had traded by August 26.
A 98.45¢ favorite won — that was never a certainty
The final pre-decision board showed 98.45¢ for the hike against 1.2¢ for no change. The settlement matched the favorite, but a 98.45¢ price still implied roughly a 1-in-70 read that something else would happen. Displayed prices are observations, not guarantees, and this cycle is a clean worked example.
Attention rotates to October 29–30
The next scheduled meeting owns the next dated search wave. At the September 18 snapshot the October event showed a displayed 82¢ no-change against 13¢ for another 25-basis-point increase, on about $118 thousand of volume and roughly $78 thousand of liquidity — the new baseline is the post-hike 1.25% guideline. The October 2026 Bank of Japan meeting guide tracks it.
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.
How attention tracked this decision — and where it goes next
The guide originally landed 46 days before the scheduled meeting, was refreshed 22 days out on August 26 and again four days out on September 13, and recorded the decision itself on September 18 — the day the date, outcome, and resolution intent peaked. The topic was not selected because the board repriced—a price move alone is not a reason to publish: the September meeting is independently scheduled on the Bank’s annual calendar, the five-outcome event finished at about $1.52 million in cumulative volume, and the dated intent reached this canonical through search across the whole cycle.
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 became most specific around the official announcement, current market status, source hierarchy, and settlement evidence. The promised decision-day update shipped September 18, hours after the statement, preserving the confirmed result for the post-decision query wave without creating a competing URL. The dated next-meeting intent now belongs to the October 2026 Bank of Japan meeting guide.
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
What did the Bank of Japan decide at the September 2026 meeting?
The Policy Board raised the guideline for the uncollateralized overnight call rate from around 1.0% to around 1.25% — a 25-basis-point increase — by a 7–2 vote. The statement was released Friday, September 18, 2026, and the new guideline takes effect September 24, 2026, alongside a complementary deposit facility rate of 1.25% and a basic loan rate of 1.5%. Board members Asada Toichiro and Sato Ayano dissented, preferring to maintain the previous guideline.
When is the September 2026 Bank of Japan meeting?
The official Bank of Japan calendar scheduled the Monetary Policy Meeting for Thursday and Friday, September 17–18, 2026. The decision was announced immediately after the meeting ended, on Friday, September 18.
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.
How did the September 2026 Polymarket Bank of Japan market settle?
Settled to the hike. At the September 18, 2026, 14:03 UTC check the event was closed: the 25-basis-point increase contract resolved to Yes at $1.00, the four other buckets closed at $0, and the event finished with about $1.52 million in cumulative volume — up from $762,690 at the September 13 check, when the board showed 98.45¢ for the hike against 1.2¢ for no change. Settlement is a recorded fact about the market; the pre-decision prices were observations, not guarantees.
What did the Polymarket board show before the September 18 decision?
The recorded path: an 86¢-versus-13¢ hike-vs-hold split at the August 26 snapshot, consolidating to 98.45¢ for a 25-basis-point increase against 1.2¢ for no change at the final September 13 check. The market then settled to the 25-basis-point increase bucket at $1.00 on September 18. The successor October event showed a displayed 82¢ no-change against 13¢ for another hike at the September 18 snapshot.
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?
This guide was updated September 18, 2026 with the full settlement record, hours after the decision. A confirmation check follows around September 24, 2026, when the new guideline takes effect, to record the final settlement state. The page now stands as the settled September record; the next dated wave — the October 29–30 meeting — is tracked by the dedicated October guide, whose decision-week refresh is expected in late October.
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, rechecked August 26, 2026, and re-verified September 13, 2026.
- 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: September 18 Change in the Guideline for Money Market Operations — official 7–2 decision to raise the uncollateralized overnight call rate guideline to around 1.25%, effective September 24, 2026; complementary deposit facility rate to 1.25%, basic loan rate to 1.5%; “continue to raise the policy interest rate” guidance; Asada and Sato dissents. Checked September 18, 2026.
- Bank of Japan: Summary of Opinions at the July 30–31, 2026 MPM — released August 10, 2026 at 8:50 a.m. JST; documents the range of Board views on the policy rate, transmission lags, and upside price risks. Checked August 26, 2026.
- Bank of Japan: Speeches 2026 — official list showing the scheduled "Economic Activity, Prices, and Monetary Policy in Japan" speeches with local leaders on September 2 (Sapporo) and September 10 (Fukui) inside the repricing window. Checked September 13, 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, plus the August 26 snapshot data (cumulative volume, liquidity, 24-hour volume, per-bucket prices). Checked August 2, 2026 at 14:05 UTC, rechecked August 26, 2026 at 14:03 UTC, rebased onto the September 13, 2026 14:03 UTC snapshot, and rechecked September 18, 2026 at 14:03 UTC for settlement: closed, 25-basis-point increase bucket resolved Yes at $1.00, final cumulative volume ≈$1.52 million.
- Public Polymarket event — live surface for current order books and contract text. Timestamped snapshots in this guide are research artifacts; executable prices live on the event page.
The July 29 publication review covered the complete 98-entry blog index, all 18 event hubs, and the 125-URL sitemap. The August 26 refresh re-ran exact and semantic scans across the complete blog archive, all 23 event hubs, the live sitemap, proactive state and refresh queue, current-day publisher output, and the latest local GSC snapshot, and the September 13 refresh repeated those scans across the complete 128-entry blog index, all 25 event hubs, the 162-URL live sitemap, and today's reactive publisher output before this update shipped. 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. The September 18 settlement refresh repeated the exact and semantic scans across the complete 132-entry blog index, all 25 event hubs, the 166-URL live sitemap, the structured proactive queue, and today's publisher output before this settlement update shipped.