Microsoft back as most valuable firm as Nvidia slips

Nvidia has handed back the position as the world's most valuable company to Microsoft after its share price fell by more than 3.5% on Thursday. The artificial intelligence (AI) chip giant briefly held the top spot from Tuesday, with a stock market valuation of 3.34tn ( 2.64tn). But Nvidia's shares fell to 130.78 on Thursday, sending its value down to around 3.22tn, with Microsoft reclaiming the title as it held steady at more than 3.3tn. Nvidia's rise has been fuelled by its dominance of what analysts call the "new gold or oil in the tech sector" - the chips that power AI. Nvidia, Microsoft and Apple - each worth more than 3tn - are in a three-horse race to be the world's most valuable company.