US Tech Giants' AI Capital Expenditure: Sustainability Risks & Market Implications

US tech giants (Microsoft, Google, Amazon, Meta) increased AI infrastructure spending by

to ~$400 billion in 2025, with plans for a further in 2026 [1]. Alphabet alone raised its 2025 capital expenditure to $850 billion amid strong Q2 performance [2]. This surge contributed ~1% to US GDP growth in 2025, acting as an economic buffer [1].

Three core challenges threaten long-term sustainability:

1. Profitability Uncertainty
   : AI projects face unclear monetization paths, with return cycles potentially exceeding 15 years [1].
2. Power Supply Bottlenecks
   : Data center electricity demand is growing at 15-20% YoY, outpacing US power supply growth of 1.8% [6].
3. Financing Pressures
   : Second-tier firms face double-digit financing rates, while even leaders rely more on debt—tech bond issuance surged to 34% of US investment-grade bonds in October 2025 [1].

Growing bubble concerns have led to tech stock corrections: NVIDIA led recent sell-offs amid valuation worries [4,5]. Market分化 is stark: leading firms (MSFT, GOOGL) maintain financial resilience, but second-tier players (e.g., ORCL) face elevated credit risks [3].

Investors should prioritize leaders with robust cash flows and diversified revenue streams (MSFT, GOOGL) while avoiding overexposure to second-tier firms with weak profitability and high debt [5].