The South Korean stock market is notoriously volatile, but concerns have spilled over into the big US companies. And with other big names such as Meta, Microsoft and Amazon reporting their latest financial results this week, investors have the opportunity to scrutinise just how much these companies are now betting on AI. On Wednesday, the tech-heavy Nasdaq ended the trading day about 9% below its June record high, driven down in part by worries over heavy AI spending. But according to leading tech investor Eileen Burbidge despite the concerns there's not yet a serious reckoning. "The AI bubble hasn't burst but it's letting out air," she told the BBC.