A Week of Two Markets: Nikkei Gains 0.95%, Then AI Selloff Hits Friday
Tokyo stocks ended a volatile week slightly higher on the Nikkei but nearly flat on TOPIX as AI-chip reversals dominated trading, while the yen and BOJ policy shaped the next-open setup.
This is market journalism, not investment advice.
Tokyo cash equities were closed Saturday. This is a weekly review and next-open setup, not a Saturday trading report.
Data checked: 2026-10-31 12:30 JST / 2026-10-30 20:30 PDT. All Japan index table figures are final closes. The 10-year JGB week-end precise closing yield and a comparable weekly USD/JPY change were not independently verified; no figures are invented for them.
Market Snapshot
Over October 26–30, the Nikkei 225 ended 0.95% higher for the week, rising from its October 23 close of 62,693.16 to 63,290.11. TOPIX was essentially flat but 0.02% lower, from 3,965.81 to 3,965.07. The rally was concentrated, not a broad victory for Japanese equities.
Friday’s final close: Nikkei 63,290.11 (−1,369.36; −2.12%); TOPIX 3,965.07 (−38.21; −0.95%). In the Prime Market, 807 shares rose and 714 fell even as index heavyweights dragged benchmarks down.
| Date | Nikkei 225 | TOPIX |
|---|---|---|
| 10月23日 / Oct 23 | 62,693.16 | 3,965.81 |
| 10/26 / Mon | 62,189.65 | 3,972.98 |
| 10/27 / Tue | 63,268.37 | 3,997.37 |
| 10/28 / Wed | 63,954.19 | 3,991.71 |
| 10/29 / Thu | 64,659.47 | 4,003.28 |
| 10/30 / Fri | 63,290.11 | 3,965.07 |
What Moved Tokyo
Monday brought another round of technology weakness. Tuesday through Thursday brought a recovery, lifting the Nikkei to 64,659.47. Friday reversed much of it. Earnings and spending concerns involving large U.S. technology companies revived questions about the valuation of AI-related shares. Japan’s price-weighted Nikkei responded more violently than its broader TOPIX. That difference is the week’s most useful signal.
Today’s Market Mover
Advantest (6857) and semiconductor testing best capture the week. Enthusiasm about AI chip demand supported the midweek recovery; Friday’s retreat showed how quickly the same sector can become a source of index risk. Underlying demand for chip testing and the valuation investors will pay for future profits are separate questions.
Confidence: High that AI and semiconductor shares drove much of the volatility; individual investors’ motives cannot be established from market prices alone.
Sector Pulse
Tokyo’s 33 industry groups split almost evenly Friday: 16 gained and 17 declined. Air, sea and land transportation were relatively firm; nonferrous metals, electrical machinery and glass and ceramics were among the weaker groups. Kioxia, Advantest, Fujikura and SoftBank Group faced pressure; Konami Group and Keyence were bright spots. The sector split shows why a large fall in the headline index does not mean every listed company sold off.
Yen Watch
Public market commentary placed dollar-yen around the low ¥157s on Friday. Foreign exchange has no single official equity-style closing auction, and a precisely comparable weekly yen change could not be verified for this edition. A weaker yen can help overseas revenues translated into yen while raising the cost of imported fuel and food; that tension matters more than any one isolated quote.
Rates / JGB Watch
The Bank of Japan kept the short-term policy rate around 1.25% at its October 30 decision, following September’s increase. Rate expectations matter for bank lending margins, property financing, corporate borrowing and the yen. A verified week-ending 10-year JGB yield was not available in the sources examined, so no exact closing yield is claimed.
Global Handoff
After Tokyo had closed for the week, Wall Street completed Friday’s session with the S&P 500 at 7,580.07 (−1.82%) and Nasdaq Composite at 25,437.00 (−2.86%). Concerns over technology valuations and the economics of AI investment persisted. Those U.S. final prices are a forward-looking input for Tokyo’s next open—not an explanation retrospectively attributed to Japan’s already completed Friday session.
Policy / BOJ Watch
The BOJ voted 8–1 to hold its policy rate, and its inflation assessment kept future tightening on the agenda. October Tokyo core CPI was reported at 2.6% year on year. The real question is whether prices and wages can reinforce one another without unduly burdening households and smaller businesses. A December hike remains an expectation, not a decision.
Publisher’s Market Note
The word “AI” meant growth on Wednesday and risk on Friday. Japan’s chip equipment makers can be essential to global industry without every share price being justified at every moment. The more useful long-term story is where innovation, household purchasing power and the price of capital meet—not simply whether one index finishes higher.
Before the Next Open
- Monday, November 2: Monitor whether Friday’s U.S. technology selloff carries into Japanese chip shares.
- Watch BOJ communication, yen movements and government-bond yields.
- Separate individual earnings surprises from the broader AI-trading narrative.
- Tuesday, November 3 is Culture Day: Tokyo cash equities will be closed for the holiday.
Sources and Method
The report uses public information only. No paid article text was reproduced. Timing and confirmation status are identified, and figures may differ across delayed services.
Archive Entry
Date: 2026-10-31
Report URL JP: /japan-market-desk/report-2026-10-31.html
Report URL EN: /e/japan-market-desk/report-2026-10-31.html
Market Mover: Advantest / AI semiconductor testing
Ticker: 6857
Theme: AI valuations · BOJ normalization · index concentration
One-Line Reason: Midweek chip-led recovery reversed sharply Friday as U.S. technology earnings rekindled AI valuation concerns.
Nikkei Direction: Up 0.95% weekly
TOPIX Direction: Down 0.02% weekly
Production Window: Saturday review / before next Tokyo open
Data Checked: 2026-10-31 12:30 JST / 2026-10-30 20:30 PDT
