The KOSPI fell 1.31 percent at the open on Friday, June 26, following tech losses on Wall Street and profit-taking after the previous session's sharp rise.
The KOSPI lost 117.12 points, or 1.31 percent, to 8,813.18 at the opening bell. By 9:15 a.m. it had fallen further to 8,777.9, down 152.4 points or 1.71 percent.
The index had gained 459.28 points, or 5.42 percent, to close at 8,930.30 on Thursday after briefly topping 9,000. The rally followed stronger-than-expected earnings from US chipmaker Micron Technology.
US stocks closed mixed overnight. The S&P 500 lost 0.01 percent, the Nasdaq composite fell 0.46 percent and the Dow Jones Industrial Average rose 0.14 percent. US consumer prices rose 4.1 percent in May, raising the possibility of a Federal Reserve rate hike.
Samsung Electronics declined 1.67 percent and SK hynix fell 1.68 percent. Hyundai Motor dropped 2.78 percent and Kia declined 2.51 percent. The Korean won traded at 1,548.3 won per dollar, down 6.2 won.