AI data center builders doubled their debt in five years to fund a historic spending spree

AI data center builders doubled their debt over five years to fund a historic spending spree, with U.S. secured debt reaching $25.4 billion in 2025. Former bitcoin miners like Core Scientific, TeraWulf, and IREN are raising billions for AI infrastructure, while the U.S. Senate investigates opaque debt structures in the sector.

AI data center builders doubled their debt in five years to fund a historic spending spree From hyperscalers to former bitcoin miners, the industry is leaning hard on debt markets to build the infrastructure backbone of the AI era The largest AI data center builders roughly doubled their total debt load over five years as capital expenditure demands from the AI boom turned into one of the most aggressive borrowing cycles the tech sector has ever seen. U.S. secured debt for data centers reached approximately $25.4 billion in 2025, a 112% jump from 2024 levels and nearly 19 times higher than where the figure sat in 2022. Big Tech opened the firehose Between September and October 2025 alone, AI-focused Big Tech raised $75 billion in U.S. investment-grade bonds. For context, the sector’s prior annual average over the preceding decade sat around $32 billion. They cleared that bar in roughly eight weeks. Former bitcoin miners want in Core Scientific is planning a $3.3 billion high-yield bond sale in April 2026 to finance its pivot toward AI data centers. TeraWulf is targeting a $3 billion debt raise in September 2025, with Google providing backing to support expansion into AI-focused facilities. IREN secured $3.65 billion in A-rated financing in June 2026, tied directly to a Microsoft AI cloud contract. What investors need to watch The U.S. Senate has opened an investigation into opaque debt structures in the AI data center space, with particular concern about how risks are being disclosed to lenders. Projections from firms including McKinsey and Morgan Stanley suggest cumulative AI data center spending will reach into the trillions by 2030. Disclosure: This article was edited by Editorial Team. For more information on how we create and review content, see our Editorial Policy https://cryptobriefing.com/editorial-policy/ .