New Delhi, Aug. 21 -- As U.S. companies raise billions of dollars to fund their AI dreams, they're primarily tapping debt markets. But the burden of debt can hurt stock investors, too.

Nearly 70% of the $456 billion cash raised for AI from the public market in 2026 has come from the investment-grade debt market, according to Bank of America Global Research. At $309 billion, that amount is more than double the $136 billion in AI-related investment-grade debt issued in all of 2025.

Much of that debt supply is coming from just five companies: Alphabet, Amazon.com, Meta Platforms, Microsoft, and Oracle. Collectively known as the hyperscalers, these five companies operate data centers that account for 71% of the world's cumulative AI compute...