AI-Heavy Capex Outpaces Revenue - A Margin Test for Big-Tech

Microsoft’s and Meta’s earnings for the quarter ended 31 December 2025 showed robust top-line growth (Microsoft +17% YoY to US$81.3b, Meta +24% QoQ to US$59.9b). However, the results revealed a structural mismatch: capital expenditures were expanding far faster than revenue. Microsoft spent US$37.5b on AI centric data-center build-out; Meta’s quarterly capex hit US$22.1b and FY 2026 guidance targets capital expenditure of US$115-US$135b.

The margin impact is already evident: Microsoft’s operating margin is projected to narrow to ~67% (its lowest in three years) while Meta’s operating margin fell from 48% to 41% despite cash-rich balance sheets. This report dissects the ROI prospects of AI driven capex, evaluates debt-service risk if interest rates are hiked, and contrasts “renter” (cloud) versus “builder” (AI-consuming) business models to identify which big-tech names are best positioned to sustain margins and generate shareholder value.