The KOSPI index is displayed at a dealing room of Hana Bank in Seoul, Friday. NewsisKorean stocks opened sharply lower Friday as investors took a breather following a recent rally in tech shares amid uncertainty over the U.S.-Iran peace deal.After opening 3.66 percent lower, the benchmark Korea Composite Stock Price Index (KOSPI) fell 449.16 points, or 5.2 percent, to 8,190.25 as of 9:15 a.m.The Korea Exchange suspended program trading for the KOSPI for five minutes at around 9:08 a.m., a measure issued when the KOSPI 200 Futures index decreases 5 percent or more for at least one minute.Overnight, major U.S. stocks closed mixed.The Dow Jones Industrial Average rose 1.73 percent, and the S&P 500 added 0.41 percent to 7,584.31. The tech-heavy Nasdaq composite slipped 0.09 percent as declines in artificial intelligence-related stocks weighed on the index.Broadcom tumbled more than 12 percent after the U.S. chipmaker's quarterly results and outlook for AI-related revenue fell short of investors' lofty expectations.Oil prices retreated after three consecutive sessions of gains, as investor sentiment improved following reports that Israel had agreed to a conditional ceasefire with Lebanon.In Seoul, large-cap shares were trading in negative terrain.Market bellwether Samsung Electronics decreased 6.69 percent, while its rival chipmaker SK hynix fell 8.83 percent.Top automaker Hyundai Motor fell 5.29 percent, and electronic components maker Samsung Electro-Mechanics went down 5.13 percent.The Korean won was trading at 1,535.15 won against the U.S. dollar at 9:15 a.m., down 5.45 won from the previous session.