Korean stocks opened at a fresh record high Thursday after a more than 6 percent rally the previous session, driven by simmering signs of a peace deal between the United States and Iran, and an extended advance in chipmakers. The benchmark Korea Composite Stock Price Index (KOSPI) added 53.34 points, or 0.72 percent, to 7,437.9 as of 9:15 a.m. After opening at a fresh record high of 7,499.07, or 1.55 percent higher, the index shot up to a new al…