The session began on an optimistic note, with the KOSPI opening 1.09% higher at 6,089.11 and briefly extending gains to as much as 3.4%. SK Hynix shares fell more than 9% on the day, after sinking even further during intraday trading. The sell-off in Seoul mirrored steep losses across U.S. chip stocks overnight, where the Philadelphia Semiconductor Index fell for a fourth consecutive session. SK Hynix's U.S.-listed depositary receipts fell nearly 9% as the sell-off extended into a third straight session on Wall Street. The development added a fresh layer of uncertainty to markets already grappling with the fallout from the chip sector's earnings disappointment.