South Korea's Kospi index collapsed more than 10 percent on Monday, prompting the Korea Exchange to activate a marketwide circuit breaker that suspended trading for 20 minutes after losses exceeded 8 percent. The sell-off marked the 42nd trading halt of the year on the Seoul bourse.
Heavyweight chipmakers bore the brunt of the rout. Samsung Electronics and SK Hynix both lost around 13 percent, extending declines that have erased nearly half their value since all-time highs last month. Samsung Electro-Mechanics fell more than 15 percent and the won weakened to 1,466 per dollar.
The turmoil swept across Asian semiconductor hubs. Tokyo's Nikkei dropped more than 4 percent, with Kioxia shedding 18 percent, while Taipei retreated over 4 percent. The rout followed a 2.2 percent decline in the Philadelphia Semiconductor Index, where Nvidia and Advanced Micro Devices gave up roughly 5 percent after The Information reported that China's Shanghai Yuliangsheng had begun mass-producing lithography technology long dominated by ASML.