South Korean shares opened lower Wednesday as investors sat on the sidelines after U.S. Federal Reserve Chair Jerome Powell said the recent stock prices are "fairly highly valued." The benchmark Korea Composite Stock Price Index lost 0.27 percent, or 9.28 points, to 3,476.91 in the first 15 minutes of trading. Overnight, the Fed chair said in a speech that equity prices may be overvalued, driving major U.S. firms, including Nvidia, to plummet. In Seoul, top tech giant Samsung Electronics shed 0.35 percent, and No. The local currency was quoted at 1,393.7 won against the greenback as of 9:15 a.m., down 1.1 won from the previous session.