Kospi Plunges 8% to Trigger Level 1 Circuit Breaker and Fall Below 5,000, Nikkei Sinks 6% as SK Hynix and Samsung Tumble Over 10%

TradingKey - KOSPI plunges 8.55%, triggering a Level 1 circuit breaker and crashing below 5,000 points; SK Hynix collapses 12%, Samsung tumbles 10%.

During Asian trading hours on November 6, Japanese and South Korean stock markets failed to reverse their risk-off slide following recent sell-offs. Weighed down heavily by overnight plunges among leading US chipmakers, benchmark indices in both countries continued to gap down at today's open, leaving market sentiment under extreme tension.

South Korea's benchmark KOSPI index opened down over 2% before losses quickly widened to 8.55%, triggering a Level 1 circuit breaker that halted trading for 20 minutes. The index has now breached the 5,000 threshold to trade at 4,923.47 points. Meanwhile, Samsung Electronics tumbled 10.07%, nearing the 180,000 level to stand at 181,200 won, and SK Hynix plunged 12.26% to 1,109,000 won.

KOSPI index chart, source: TradingView

The Nikkei 225 index gapped down at the open to 60,374.35 points. Selling pressure on semiconductor equipment and export stocks continued to mount after the opening bell, rapidly widening the index's decline to 6.2% and directly breaching the key 60,000-point threshold to hit 57,288.91 points.

After Democrats regained the House and took control of the Senate, Wall Street's concerns over Alphabet (GOOG), Amazon (AMZN), Microsoft (MSFT), and Meta (META) regarding AI data center energy consumption, carbon emissions, and antitrust scrutiny continued to spread, triggering a sell-off in the AI and chip sectors, with the Nasdaq Composite Index tumbling over 5%, the Philadelphia Semiconductor Index plunging 12%, SanDisk (SNDK) crashing over 22%, and Micron Technology (MU) and Western Digital (WDC) both falling more than 17%.

The collective collapse of US semiconductor giants sent an extreme risk-off signal directly to the Asia-Pacific supply chain, triggering indiscriminate liquidation at today's open across core Japanese and South Korean supply chain players such as SK Hynix, Samsung Electronics, and Advantest. Going forward, attention will focus on whether institutional investors, including South Korea's National Pension Service (NPS), will activate stabilization funds to step in and support the market if morning losses widen.