Big tech's $750B AI bet strains as core growth slows

America's biggest technology companies are seeing their core businesses slow even as they maintain a combined $750 billion in AI spending this year, with Alphabet's stock plunging a record amount and Amazon's shares falling 7% after weak earnings reports. Alphabet's search ad growth hit its slowest pace in five quarters, while Amazon's ecommerce and advertising growth slowed, with online stores up just 2%. Both companies kept capital spending plans, and investors are questioning how AI investments will pay off, especially as new AI features reduce profitability of legacy products. Microsoft's Azure cloud grew 48% but its stock still fell, while Google's cloud division doubled sales. Companies are issuing debt and signing data center deals, betting on future AI agents that can make purchases, though current AI features like Google's AI Mode show lower monetization.