Shares of Samsung Electronics and SK Hynix fell more than 7% in early Thursday trading, dragging down South Korea's benchmark Kospi index.
The sharp decline in Seoul followed a heavy overnight slump in the tech-heavy Nasdaq Composite, signaling that the recent semiconductor sector weakness is broadening across global markets.
Pressure on the Kospi intensified on Tuesday, when the index crashed nearly 10%, triggering a 20-minute trading halt as a massive sell-off engulfed the technology sector.
The selloff in South Korean memory chip stocks extends a volatile week for the sector.
Shares of both Samsung and SK Hynix dropped sharply on Monday after reports emerged that the two companies are preparing to announce combined investment plans totaling more than $1.3 trillion.
The sheer scale of the proposed capital expenditure sparked investor concern regarding return on investment and potential overcapacity in the memory market.
Pressure on the Kospi intensified on Tuesday, when the index crashed nearly 10%, triggering a 20-minute trading halt as a massive sell-off engulfed the technology sector.