KOSPI slid 3.65 percent Monday, falling below 6,400 as its losing streak stretched to four consecutive sessions. The benchmark index has shed 619.50 points, or 8.85 percent, since Oct. 6. After losing the 7,000 mark earlier in that stretch, it breached both the 6,500 and 6,400 levels on Monday. Persistent selling by foreign investors has weighed on KOSPI, leaving it struggling to recover even after Samsung Electronics reported record earnings last Thursday. After opening 47.76 points, or 0.72 percent, lower at 6,578.17, the index extended its losses to close at 6,384.24, down 241.69 points, or 3.65 percent. It marked the benchmark’s biggest daily percentage decline since Sept. 2, when it fell 3.99 percent. Samsung Electronics and SK hynix, the market’s two leading chip stocks, dropped 4.39 percent and 4.52 percent, respectively, dragging KOSPI lower. “The two chip heavyweights came under pressure as investors weighed renewed concerns about an artificial intelligence (AI) bubble following reports about OpenAI,” said Kim Seok-hwan, an analyst at Mirae Asset Securities. Reports on Thu