Seoul shares plummeted 5.4 percent Wednesday as technology stocks extended their losses and investors reassessed the outlook for artificial intelligence trade. The Korean won rose against the US dollar. After opening 2.7 percent lower, the benchmark Korea Composite Stock Price Index extended losses to close down 409.52 points, or 5.4 percent, at 7,246.79. Trade volume was heavy at 495.75 million shares worth 41.65 trillion won ($27.78 billion), with decliners outnumbering gainers 763 to 124. For