An electronic board showing the Korea Composite Stock Price Index at a dealing room of the Hana Bank headquarters in Seoul on Monday. (Yonhap) Seoul stocks opened sharply lower Monday as investors went to lock in profits after a record-breaking surge the previous session.After opening 3.6 percent lower, the benchmark Korea Composite Stock Price Index fell 280.05 points, or 4.25 percent, to 6,315.4 as of 9:15 a.m.The index bucked a rally on Wall Street on Friday, as robust earnings from Amazon fueled investor optimism for the artificial intelligence sector.Revenue at Amazon's cloud computing unit jumped 37 percent in the second quarter ending in June, exceeding market expectations."We may see investors attempt profit-taking early this week, as the benchmark KOSPI vaulted around 17 percent Friday, the sharpest single-day gain on record," Han Ji-young, an analyst from Kiwoom Securities, said.Tensions in the Middle East have shown signs of easing as US President Donald Trump said talks with Iran will resume Monday after he called off a "massive attack" on the country.In Seoul, most large-cap shares were trading lower.Chip giant Samsung Electronics fell 6.48 percent, while industry rival SK hynix dipped 6.69 percent.Battery maker LG Energy Solution fell 4.27 percent, major financial company KB Financial inched down 0.47 percent, while defense giant Hanwha Aerospace added 0.55 percent.The Korean won was quoted at 1,433.3 won against the US dollar, up 2.2 won from the previous session. (Yonhap)