A Bank of America survey of institutional credit investors reveals a growing concern over an "AI bubble," with 23% identifying it as their primary worry, a significant increase from 9% in December 2025. This sentiment is amplified by the projected $700 billion in AI-related capital expenditures by major hyperscalers like Alphabet, Microsoft, Meta, and Amazon in 2026, raising questions about the return on investment for these massive infrastructure costs. While no major AI companies have seen credit rating downgrades yet, some, like Microsoft, have disclosed substantial backlogs tied to entities like OpenAI, whose $300 billion deal with Oracle includes projections of significant cash burn. Bond market indicators, such as widening credit default swap pricing for companies like Oracle, suggest increased skepticism about AI-related debt sustainability, contrasting with the general continued investment in AI stocks by the equity market.