(LEAD) Seoul shares soar over 6 pct on revived AI optimism, SK hynix earnings

Seoul's stock market surged over 6 percent on Wednesday, driven by a rally in chipmakers following strong earnings from SK hynix. The Korean won weakened against the US dollar. The benchmark KOSPI index climbed 374.1 points, or 6.63 percent, to close at 6,012.44 after reaching a high of 6,032.28. The market's rally was fueled by tech gains, prompting the Korea Exchange to activate a buy-side sidecar shortly before 11 a.m., temporarily suspending program trading for five minutes.

This measure was triggered when KOSPI 200 futures rose by at least 5 percent and maintained that level for at least one minute. Earlier, SK hynix reported record revenue and operating profit for the third quarter, attributed to robust demand for memory chips fueled by the artificial intelligence (AI) boom. The company announced a shareholder return program worth over 100 trillion won (US$75.3 billion) for 2026 to address concerns about the sustainability of the AI-driven rally and potential peak in the memory chip cycle.

Analysts noted that SK hynix's strong performance in AI chips indicates solid operating profits and potential shareholder returns, easing worries about the rally's longevity. Among the biggest gainers were Samsung Electronics, which jumped 9.01 percent to 242,000 won, and SK hynix itself, which soared 10.89 percent to 1.49 million won.

Other notable winners included SK Square, the parent company of SK hynix, up 11.23 percent to 921,000 won, and Samsung Electro-Mechanics, an electronics component affiliate of Samsung Electronics, which surged 8.74 percent to 1.3 million won.