SK Hynix Shares Tumble in Seoul After Strong Nasdaq Debut, Dragging Kospi Down Sharply

Shares of SK Hynix tumbled more than 15% in Seoul, marking the memory chipmaker's worst trading day, after a strong Nasdaq debut prompted investors to lock in profits and reassess the valuation of artificial-intelligence-linked semiconductor stocks. The South Korean company's US-listed shares had jumped about 13% on their Wall Street debut, reflecting strong appetite among American investors for AI memory exposure. The sharp reversal in Seoul dragged the benchmark Kospi index down almost 9% to close at 8,806.93, while the small-cap Kosdaq fell 4.6% to 799.36. Analysts said the decline reflected a mix of profit-taking and genuine uncertainty over how the US-listed shares should be valued relative to the Korean line, noting that the American depositary receipt debut has effectively created a new benchmark against which investors will assess the company. The episode underscores how concentrated South Korea's equity market has become around a small number of chip giants riding the AI investment boom, and how quickly sentiment can swing when investors question whether surging demand for advanced memory justifies the stocks' steep run this year.