Based solely on the article body, Microsoft and Amazon reported on April 29, 2026, revealing different clocks on AI cloud ROI. Microsoft’s AI business surpassed an annual revenue run rate of $37 billion, up 123% year-over-year, with over 20 million paid Copilot seats. Amazon’s AWS grew 28% to $37.59 billion, and its Trainium chip business crossed a $20 billion run rate. However, Amazon’s Q1 capex ran $44.2 billion against $26.0 billion in operating cash flow, producing negative free cash flow of $18.2 billion. Amazon’s $132 billion 2025 capex wave enters full revenue service in mid-2027, when owned Trainium silicon begins compounding against Microsoft’s ongoing NVIDIA cost obligations. Andy Jassy secured over $225 billion in Trainium commitments from Anthropic and OpenAI, pre-selling capacity that promises several hundred basis points of operating margin advantage at scale. Jassy stated Trainium will save tens of billions of dollars of CapEx each year and provide several hundred basis points of operating margin advantage.