Four companies -- Oracle, Amazon, Microsoft and Google -- now account for a combined commitment of more than $870 billion in AI infrastructure spending this year, a concentration of capital so large that the Bank for International Settlements, the institution often called the central bank for central banks, has directly warned it carries systemic financial-stability risk.
Oracle sits at the center of that warning: its $300 billion Stargate commitment alongside OpenAI requires the company to borrow roughly $25 billion a year just to keep financing its share of the buildout, even as its stock has fallen more than 40% over the past month. The BIS specifically flagged that OpenAI itself cannot yet self-fund its own operations, meaning Oracle is financing capacity for a customer still dependent on external capital to survive.
Amazon, Microsoft and Google are committing comparable sums -- more than $200 billion, $190 billion and $180 billion respectively this year -- but with a meaningfully different financing structure: all three fund the bulk of their AI capex from existing free cash flow rather than the debt-heavy structure underpinning Oracle's Stargate exposure, a distinction the BIS explicitly draws in separating systemic risk from company-specific risk.
The historical comparison the BIS invokes is not the dot-com bust but 19th-century railway mania -- a period defined less by the technology's eventual usefulness (railways were, in fact, transformative) and more by debt-financed overbuilding that outran near-term demand, leaving overleveraged operators exposed when growth assumptions didn't hold.
For infrastructure and credit investors, the practical distinction to underwrite is exactly the one the BIS draws: hyperscaler capex funded from free cash flow is a fundamentally different risk than capex financed through debt against a single customer's future revenue, even when both show up as similarly large headline numbers.
What to watch: whether Oracle's borrowing costs rise as credit markets continue pricing in the BIS's concerns, whether OpenAI's revenue growth trajectory can plausibly catch up to the infrastructure built around it, and whether Amazon, Microsoft or Google show any signs of pulling back their own capex guidance in response to the broader bubble warnings.