Nikkei 225 closes at 64075.42, down 1.30%, as Asian chip stocks fall

The Nikkei 225 closed at 64075.42 on Tuesday, October 20, 2026, down 841.28 points or 1.30% from the previous close of 64916.7. Asian equities were weak as chip-related shares fell in South Korea.

What happened

Tokyo's benchmark index finished the session at 64075.42, as of 15:25 Asia/Tokyo. The previous close was 64916.7. The change of -841.28 points equals -1.30%.

The Tokyo Stock Exchange trades in two sessions each day, from 09:00 to 11:30 and from 12:30 to 15:30 Asia/Tokyo. The index level of 64075.42 was recorded at 15:25 Asia/Tokyo, near the end of that trading day.

The index lost 841.28 points in one session. It had ended the previous session at 64916.7, so the day's decline took back part of that level.

Currency and regional markets

The yen was a little stronger against the dollar. USD/JPY stood at 158.12 at 06:45 UTC. That compares with a previous close of 158.46, a change of -0.34 or -0.21%.

A lower USD/JPY figure means that one dollar buys fewer yen than it did at the previous close. The move in the currency was smaller than the move in the equity index, which fell 1.30%.

Across the region, the main pressure came from South Korea. One report said the KOSPI lost another 5% in a single session as the rout in artificial intelligence-related shares deepened. An earlier report from the same day put the drop at more than 2%. The two figures were written at different times in the Asian session, and the index was still moving.

SK Hynix, a chip heavyweight, headed for its lowest close since April. Reports said SK Hynix and Samsung have fallen 35% and 22%, respectively. One report described the AI bellwether as down over 40% from its peak. The KOSPI is seen as a bellwether for artificial intelligence investment.

Elice, a data-center infrastructure company, fell as much as 32% in its trading debut in Seoul. The Asian decline came as a break from a rally in US chip shares noted in one market report. That means the regional weakness did not follow a fall in US chip stocks.

The background and the previous values

The Nikkei 225 stood at 64916.7 at the previous close and at 64075.42 at the end of this session. The difference is 841.28 points. USD/JPY moved from 158.46 at the previous close to 158.12 on Tuesday.

The September trade figure due later is the only high-impact calendar row for Japan today. The previous reading was -1105.6 B, and the estimate for September is -181 B. A trade balance records exports minus imports, so a negative figure means imports were larger than exports in that month.

The weakness in South Korean chip shares is the main regional theme in the news flow. SK Hynix and Samsung are both large chip makers, and both are named in the reports as leading the decline. Elice's debut adds a data-center name to the list of stocks under pressure.

The reports also describe how deep the losses run. SK Hynix is down 35% and Samsung is down 22%, and one report put the AI bellwether more than 40% below its peak. A single-session loss of 5% in the KOSPI, as one report stated, is a large move for a national benchmark.

In Tokyo, the session produced a 1.30% decline for the Nikkei 225, which left the index at 64075.42. The currency market was calmer, with USD/JPY down 0.21% from its previous close of 158.46.

Why it matters

Japan and South Korea both host large technology and chip-related companies. A sharp fall in one market can affect sentiment in the other. The Nikkei's 1.30% decline came on a day when South Korean chip shares were under heavy pressure.

The yen level also matters for Japanese exporters and for the trade data. USD/JPY at 158.12 means one dollar buys 158.12 yen. The currency moved less than the equity index, with a change of -0.21%.

The reports describe the KOSPI as a gauge of artificial intelligence investment. When that gauge falls sharply, the effect can reach other Asian exchanges where AI-linked companies are listed. The Elice debut, with a fall of as much as 32% on its first day, shows how stretched sentiment toward AI-related listings was in Seoul.

The contrast with the US session is also part of the picture. One market report framed the Asian decline as a break from a US chip rally, so the regional moves ran against the direction set by US chip shares.

What to watch next

Japan publishes its September balance of trade at 23:50 UTC on October 20. The estimate is -181 B, and the previous figure was -1105.6 B. The actual figure has not been released yet.

Market participants will also follow whether the decline in South Korean chip shares continues, and how the Nikkei 225 trades in the next session against the close of 64075.42. The next reading of USD/JPY will be compared with the 158.12 level and the previous close of 158.46.

Attention will also stay on SK Hynix and Samsung, whose declines of 35% and 22% are central to the regional story. Further trading in Seoul will show whether the lowest close for SK Hynix since April is repeated or extended.