Tokyo’s AI Selloff Deepens: October 22 Close and October 23 Midday

Market Snapshot

Thursday, October 22, closed with the Nikkei 225 at 62,907.84, down 1,713.40 points (2.65%), and TOPIX at 3,997.50, down 46.23 points (1.14%). The Nikkei ended at its session low and beneath 63,000, a stark reversal from Wednesday’s 64,621.24 close.

Friday’s data belongs to a separate, unfinished session. At 9:49 a.m. JST October 23, a public intraday report put the Nikkei at 61,922.39, down 985.45 points (approximately 1.57%), and TOPIX at 3,951.12, off 46.38 points (approximately 1.16%). The final 11:30 a.m. morning-session closes were not independently confirmed for this edition. They are deliberately not invented.

What Moved Tokyo

Thursday’s plunge was not a simple reaction to a bad Wall Street close: U.S. stocks had actually gained on Wednesday. Investors in Tokyo instead grappled with the cost of the AI infrastructure build-out, weakness in semiconductor-equipment names, a falling Korean market and growing anxiety about global risk.

The distinction between Japan’s two benchmarks matters. The Nikkei lost 2.65%, more than twice TOPIX’s 1.14% decline. On the Prime Market 821 stocks fell and 684 rose. The market was broadly weak, but the index’s extreme move was amplified by its sensitivity to several high-priced technology shares.

Today’s Market Mover

Advantest (6857) and Tokyo Electron (8035) form our market-mover story. A public index-contribution analysis showed the two semiconductor bellwethers accounting for roughly 805 points of Thursday’s 1,713-point Nikkei decline. This is a measure of index impact, not a calculation of dollars or yen lost in the firms’ combined market value.

Friday morning brought signs of an attempted bounce off early lows in some chip names. Yet at 9:49 a.m. the Nikkei remained nearly a thousand points below Thursday’s close. One rebound within a volatile morning is not a durable sector recovery. Confidence: High for Thursday’s measured contribution; Medium for explanations of Friday’s continuing pressure.

Sector Pulse

Nonferrous metals, glass and ceramics, and electrical equipment ranked among Thursday’s weaker Tokyo sectors. Insurance, services and mining held up better. Chip-linked names including Ibiden, Kioxia, Lasertec and SCREEN declined, while Trend Micro and several services shares gained in public market summaries.

No full, independently checked Friday morning sector leaderboard was available at the editorial cutoff. We therefore do not present Thursday’s ranking as Friday’s result.

Yen Watch

A public bank quote placed USD/JPY at 157.04 at 5:56 p.m. JST on Thursday. A separately reported Friday 9:40 a.m. quote put the rate at 156.09. These observations are not simultaneous, but show the yen strengthening between the two checkpoints.

A firmer yen can squeeze exporters’ yen-denominated overseas earnings even as it offers relief on imports of energy and food. It would be misleading to attribute the entire equity decline to exchange rates alone.

Rates / JGB Watch

A Thursday afternoon Japanese bond-market report put the benchmark 10-year JGB yield near 2.870%; a separate historical-data provider reported 2.876% for October 22. These are dated source observations, not one synchronized official settlement. The yield picture is important because Japan’s banks, insurers, property companies and high-duration growth businesses respond differently to rate changes.

In the United States, the October 22 technology selloff coincided with a strong Treasury rally and falling long-term yields, Reuters reported. Lower yields can signal growing concern about future demand as readily as optimism about easier financing.

Global Handoff

The October 22 global handoff was hostile to technology: Reuters reported the Nasdaq down around 2.6% and the U.S. semiconductor index down about 6.7%. European shares also slipped, with the STOXX 600 lower by roughly 1.05%.

At noon Friday in Tokyo, the October 23 European and U.S. cash sessions had not begun. This analysis uses the latest completed overseas session, rather than making up a same-day overseas reaction.

Policy / BOJ Watch

The Bank of Japan is approaching its next policy meeting amid a different problem from the one that dominated Japan’s old deflation era: how to respond to persistent price pressures without choking off business investment. A strengthening yen could lower imported costs, but wage trends and domestic services inflation still matter.

Japan’s nationwide CPI release was on the October 23 calendar. The precise release figures were not independently verified at the editorial cutoff and are not supplied here as fact. A bruising stock-market session alone tells us little about what the BOJ will decide.

Publisher’s Market Note

When the Nikkei moves more than a thousand points, it can seem as though all of Japan changed overnight. Yet the more durable story may be the collision of three clocks: the seconds of an equity trade, the years it takes a new semiconductor plant to earn a return, and the monthly household bill affected by the yen. Japan’s economy lives on all three timelines. A good market desk should never confuse them.

Before the Next Open

• Friday’s actual Tokyo closing prices, and whether morning losses deepen or reverse.
• Advantest and Tokyo Electron versus the next U.S. semiconductor session.
• USD/JPY around the 156 area and movements in Treasury yields.
• Oil, Middle East risks and their impact on energy importers.
• Official Japanese inflation releases and BOJ signals.

Sources and Method

This report uses publicly accessible price history, dated market reporting and official policy links. Quotes from different sessions are not synchronized. No subscription-only article text is reproduced.

1. Nikkei Indexes — official daily historical prices
2. Kabutan — Oct. 22 Tokyo cash closing report
3. Kabutan — Oct. 22 index contributor analysis
4. SBI Shinsei Bank — dated FX and index quotes
5. Bank of Japan — policy announcements

October 23, 9:49 a.m. observation: 公開時刻付き市場観測 / timestamped market observation. Overseas context: Reuters, October 22.