TradingKey - On October 19, Japanese and South Korean stock markets came under pressure again in early trading. The South Korean market recovered somewhat after opening lower, while losses in Japanese stocks widened further. The Korea Composite Stock Price Index (KOSPI) opened down 3.17% at 5,488.41 points before narrowing its decline to 1.16% at 5,602.12 points; Japan's Nikkei 225 Index opened 0.77% lower at 64,819.56 points and subsequently fell 1.73% to 64,194.90 points.

Source: TradingView
South Korean semiconductor leaders continued to slide in early trading, with Samsung Electronics falling 0.93% to 213,500 won (about $160) and SK Hynix dropping 1.18% to 1.257 million won. In the Japanese market, Kioxia fell 2.58% to 13,030 yen (about $83), and SoftBank Group declined 4.43% to 4,725 yen.
U.S. stocks suffered a tech sell-off in the previous trading session as concerns over the prospects of the AI trade continued to build. The Dow Jones Industrial Average fell 0.34% to 52,002.41 points; the S&P 500 Index dropped 1.09% to 7,659.44 points; and the Nasdaq Composite Index fell 2.15% to 26,140.03 points. Both the S&P 500 and the Nasdaq recorded their largest single-week losses in nearly four months, though the Dow posted a second consecutive week of gains.
Weakness in the semiconductor sector was particularly pronounced, with the Philadelphia Semiconductor Index falling for an eighth consecutive trading session, marking its longest losing streak since the 2008 global financial crisis. Stocks across the AI supply chain faced widespread sell-offs, with AI cloud service provider CoreWeave (CRWV) closing down over 10%, optical communications firm Coherent (COHR) dropping over 7%, SanDisk (SNDK) falling nearly 7%, and Oracle (ORCL) slipping nearly 5%. Market concerns over massive capital expenditures on AI infrastructure, debt financing costs, and future investment returns continue to weigh on related stocks.