SK Hynix reported second-quarter net profit of 93.9 trillion won, up 1,242 percent year-on-year, yet its shares fell as much as 16 percent while Samsung Electronics shares dropped nearly 10 percent. The Kospi index slid as much as 12.6 percent, reaching its lowest level since early April, amid concerns that AI infrastructure spending may be slowing. Brent crude rose 3.6 percent to $87.14 a barrel in the same session.