'Black Tuesday' in Seoul: SK Hynix sinks 10%, Samsung 7.4% on China chip fears

A sell-off in chip stocks rattled the Seoul stock market on Tuesday. SK Hynix closed down 10.09% at 1.443 million won and Samsung Electronics fell 7.39% to 232,000 won, the JoongAng Daily newspaper reported. Both had already lost about 4.5% on Monday. The benchmark Kospi dropped more than 7% at one point, below 6,000, before trimming losses to trade 5.5% lower at 6,035, The Associated Press reported.

Shortly before 10 a.m. local time, the exchange triggered a so-called sidecar, halting programme sell orders for five minutes after Kospi 200 futures fell more than 5%, according to media reports. Foreign investors sold about 1.8 trillion to 1.9 trillion won worth of shares in the morning session alone. Tech stocks also slid in Tokyo, where SoftBank lost 8.5%, Tokyo Electron 7.2% and the Nikkei 1.8%, according to AP.

The trigger was progress reported by Chinese DRAM maker CXMT, which plans to launch DDR5 server modules by year-end and reports progress with denser 4F² technology. CXMT could increasingly challenge Samsung, SK Hynix and Micron, AP said. Adding to the pressure were doubts over whether massive AI investments will pay off; Brent crude remains above $100 a barrel, AP reported.