Seoul shares ended higher Thursday as institutional buying helped offset heavy retail selling amid a reassessment of the outlook for artificial intelligence demand. The Korean won fell against the US dollar. After opening 3.3 percent higher, the benchmark Korea Composite Stock Price Index trimmed earlier gains to close up 45.12 points, or 0.62 percent, at 7,291.91. Trade volume was moderate at 574.75 million shares worth 37.46 trillion won ($24.9 billion), with decliners outnumbering gainers 651