AI-related debt issuance fell more than 50% in September 2026, according to Financial Times reporting, as investors demanded higher risk premiums. The discussion has since moved to scale: hyperscalers are issuing $500 to $600 billion in bonds in total, about what the US borrows in three to four months, and AI-related corporate issuance is up 50 percent since 2022. One estimate puts AI-related issuance at about 3.6 percent of GDP, 50 percent more than railroads and triple highways and telecoms. Morgan Stanley counts $466 billion of AI-linked debt raised this year, up from $101 billion a year earlier. Yardeni argues the AI corporate bond rout triggered a flight to quality that stopped the Treasury rout. What remains open is whether…