(Bloomberg) -- A key stock-market theme of 2025 has been the slide in shares that stand to lose out from advances in artificial intelligence, chief among them being advertising agencies.Beset by contract setbacks, Britain’s WPP Plc has plunged 60% this year, while rivals including Publicis Groupe SA and Omnicom Group Inc. have fallen by a lesser extent amid broader fears that AI will replace much of the manual work behind advertising.Yet a school of thought is developing among analysts that these companies ...