Giant Aramco listing a critical test for young Saudi exchange

RIYADH/DUBAI (Reuters) - The imminent listing of oil giant Aramco will be a pivotal moment for Saudi Arabia's young and untested Tadawul stock exchange.The Tadawul has said it has been preparing for years and is primed for the long-awaited share sale in coming weeks.Mega-IPOs have a record of causing technical glitches on stock markets as they can lead to a surge in trading orders that swamp an exchange's system and can prevent investors from buying or selling stock.