Mucahithan Avcioglu
30 July 2026•Update: 30 July 2026
- Samsung, SK Hynix lose 18.5%, 27.2%, respectively, over 3 sessions
South Korea’s stock market has erased an estimated $2 trillion in value from its June peak as a sharp reversal in artificial intelligence and semiconductor shares continued Thursday.
The benchmark Korea Composite Stock Price Index, or Kospi, fell 1.23% to close at 5,593.56 points Thursday, extending losses after plunging 10.84% Tuesday and another 5.98% Wednesday.
The index fell to an intraday low of 5,262.77 points Wednesday, representing a 43.9% decline from its record intraday high of 9,385.59 reached on June 19 — a period of exactly 40 calendar days.
The widely circulated claim that the South Korean market crashed 44% therefore reflects the maximum intraday peak-to-trough decline, rather than the change between closing levels.
At Thursday’s close, the KOSPI remained about 38.6% below its record closing high of 9,114.55 reached on June 22.
Published estimates put the loss in South Korean equity market capitalization at about $2 trillion to $2.18 trillion since the market peaked.
Tech and AI stocks lead losses
Major semiconductor and AI-linked companies have borne the brunt of the selloff.
Samsung Electronics shares dropped 13.39% on Tuesday, 5.23% Wednesday, and another 0.72% on Thursday, bringing their cumulative three-session decline to about 18.5%.
SK Hynix fell 14.65% on Tuesday, 9.61% Wednesday, and 5.64% on Thursday, losing approximately 27.2% over the three sessions. The memory chip producer’s shares are now estimated to be about 55% below their June peak, while Samsung is roughly 44% below its high.
Naver, one of South Korea’s largest internet and AI companies, lost 6.67% on Tuesday and another 4.05% on Wednesday, amounting to a two-day decline of about 10.4%.
SK Square, the parent company of SK Hynix, sank 15.6% on Tuesday, while semiconductor equipment manufacturer Hanmi Semiconductor fell 12.22%.
The declines came despite record quarterly results from Samsung and SK Hynix, as investors focused instead on whether massive expenditures on AI data centers and chipmaking capacity would generate sufficient long-term returns.
Investor concerns have also intensified over rising competition from Chinese memory-chip manufacturers, particularly following the stock market debut of ChangXin Memory Technologies and reports of progress in China’s domestic chipmaking equipment industry.
