WPP sent jitters across Madison Avenue with an unexpected profit warning Wednesday. The threat of AI isn't helping.

WPP shares sank Wednesday on the advertising giant’s second profit warning of the year, as it said clients were spending less and it was attracting fewer new clients than hoped.

Key Takeaways WPP lowered its guidance and warned of a pullback in client spending, citing a "challenging economic backdrop."The big ad agency reported a bigger-than-expected drop in second-quarter business,