[Market Recap] Nikkei Plunges 2,694 Yen to 64,141 as AI Chip Stocks Tumble – Kioxia Halves in a Month, Tonight’s Focus: June Retail Sales [2026/7/17]

Hey everyone, Hirokichi here.

Tokyo’s stock market saw heavy selling all day today (July 17). The Nikkei 225 closed down 2,694 yen at 64,141 yen – the fifth-largest single-day drop in the index’s history. Let’s break down what happened, starting with the sharp plunge in chipmaker Kioxia Holdings.

Japan’s Market Today: Nikkei Posts Its 5th-Largest Drop Ever, Closing at 64,141 Yen

The Nikkei 225 closed at 64,141.12 yen, down 2,694.42 yen from the previous day (source: Nikkei CNBC Online). During the session it fell more than 4,000 yen at one point, marking the fifth-largest intraday decline on record (source: Nikkei).

TOPIX (the Tokyo Stock Price Index, which tracks the broader Prime Market) also fell sharply, closing down 102.87 points at 3,925.92 (source: Yahoo! Finance Japan).

Behind the move was Wall Street’s overnight selloff: the Nasdaq Composite fell 1.47% and the Philadelphia Semiconductor Index (SOX) dropped 4.7% on July 16 (source: Minkabu FX). That weakness carried straight into Tokyo, where AI and semiconductor names led the decline.

(1) The Trigger: Kioxia’s Plunge and a Broad Semiconductor Selloff

Today’s biggest story was Kioxia Holdings. Selling hit the stock right from the open, and it briefly fell 10,000 yen to 52,110 yen – the daily limit-down level (source: ITmedia News). That’s less than half of its intraday all-time high of 112,700 yen set just last month in June.

The trigger was a US patent lawsuit: a federal jury in Texas found Kioxia infringed on flash-memory patents held by US satellite communications company Viasat and ordered damages of roughly $229 million (about 37 billion yen) (source: Nikkei). Reports say Kioxia’s market capitalization has shrunk by about 30 trillion yen from its June peak (source: Bloomberg). I’ll be honest – I was surprised to see a stock lose half its value that fast.

Among other chip names, Advantest, which carries heavy weight in the Nikkei 225, alone pulled the index down by about 772 points and was the single biggest drag on the day (source: Zaikei Shimbun). Tokyo Electron, SoftBank Group, Ibiden, TDK, Fanuc, Fujikura, Lasertec, Murata Manufacturing, SCREEN Holdings, Taiyo Yuden, Disco, Shin-Etsu Chemical, and Kyocera – all heavyweight AI and chip-related names – also fell broadly. Rising crude oil prices tied to Middle East tensions and higher US long-term interest rates added to the cautious mood.

(2) Currency: Dollar-Yen Holds in the Mid-162 Range on Oil-Driven Dollar Buying

In the currency market, the dollar-yen pair traded around the mid-162 yen level, recovering from an early low of 162.29 yen to around 162.50 yen (source: Kabutan). Rising crude oil prices amid Middle East tensions have been supporting dollar buying, and the market is watching a forecast range of 161.60-163.00 yen. I covered the oil price and inflation risk angle in more detail in my earlier post, “Trump Declares US ‘Guardian of the Strait of Hormuz’ – What It Means for Japan” (in Japanese), so feel free to check that out too.

(3) Tonight’s US Market Outlook: Watch June Retail Sales and Netflix Earnings

Overnight on July 16, US markets also retreated: the Dow Jones Industrial Average fell 105.67 points to 52,552.97, the S&P 500 fell 38.63 points to 7,533.77, and the Nasdaq Composite fell 387.28 points to 25,881.95 (source: Minkabu FX). As of Friday morning Tokyo time, US index futures were also pointing lower, with Dow futures down 180 points, S&P 500 futures down 31 points, and Nasdaq 100 futures down 226 points (source: Kabutan) – suggesting another cautious start tonight.

Tonight’s key data releases include June retail sales (a gauge of consumer spending strength) and weekly initial jobless claims, along with the July Philadelphia Fed manufacturing index, the July NAHB housing market index, and June pending home sales. On the earnings front, State Street, GE Aerospace, UnitedHealth Group, and Abbott Laboratories report before the opening bell, while Netflix reports after the close (source: Gaitame.com).

In chip news, TSMC (Taiwan Semiconductor Manufacturing Company) beat earnings estimates on July 16, but a sharp upward revision to its capital spending plans raised concerns about future margin pressure, and its stock fell more than 5%. If that theme continues, caution around the semiconductor sector as a whole could persist tonight as well.

Wrapping Up

Here’s today’s recap:

– The Nikkei 225 closed down 2,694 yen at 64,141 yen – its 5th-largest drop ever
– TOPIX fell 102.87 points to 3,925.92
– Kioxia Holdings briefly hit limit-down after losing a US patent lawsuit, dragging semiconductor stocks down with it
– The dollar-yen pair held in the mid-162 range, supported by oil-driven dollar buying
– Tonight, watch June retail sales and Netflix’s earnings

Semiconductor stocks remain volatile. Depending on how Wall Street reacts tonight, tomorrow’s Tokyo session could see another big swing, so I’ll keep watching closely. Let’s keep at it, slow and steady. See you next time!

Previous market recap (in Japanese): Nikkei Surges 500 Yen in a Reversal After Falling 900 Yen at the Open – Tonight’s Focus: US CPI and Fed Chair Testimony [2026/7/14]

日本語版はこちら → 日経平均一時4,000円安、終値2,694円安の64,141円！AI半導体総崩れでキオクシア半値割れ

* This article is for informational purposes only and is not investment advice. Please invest at your own responsibility.

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