The memory chip sector is trading lower in the pre-market session after SK Hynix, a key industry player, reported record second-quarter profits that still fell short of analyst expectations. The company's operating profit of 60.5 trillion won missed the forecast of 64 trillion won, triggering a sell-off. SK Hynix shares plunged nearly 7% in pre-market trading, leading to broader weakness across the sector, including a drop in Samsung Electronics shares.