The Hidden Warning Bond Traders Are Sending About Big Tech

Credit markets are starting to price in a risk that stock investors have mostly shrugged off: the debt-fueled AI buildout at the four largest hyperscalers is getting riskier, not safer. Apollo Global Management’s chief economist Torsten Slok flagged this week that credit default swaps on hyperscaler bonds — essentially insurance against a default — have widened by roughly 60 basis points relative to the banks that underwrite their debt since October 2025. That gap had sat near zero for years. For patient investors, this is worth watching closely, because bond markets have a long history of smelling trouble in balance sheets before equity markets do.

The numbers explain the unease. Alphabet is running a forward debt-to-equity ratio of 13% alongside negative free cash flow of $25.7 billion. Amazon’s debt-to-equity sits at 23% with free cash flow of negative $30 billion. Meta’s leverage is highest at 34% debt-to-equity, also with $25.7 billion in negative free cash flow. Microsoft is the outlier of the group, at just 7.3% debt-to-equity and a positive $33.4 billion in free cash flow — a reminder that not all AI capex stories carry the same balance-sheet risk. Slok’s point isn’t that these companies can’t service their debt today; it’s that CDS investors, some of the most sophisticated credit analysts anywhere, are attaching materially more risk to a debt-financed capex cycle with uncertain payback timelines on rapidly depreciating chips and data centers.

Bulls have a reasonable counter: margins at the hyperscalers are already inflecting positive, and the payoff from this capacity may not show up cleanly until 2027 or 2028. That’s a fair rebuttal, but it also means today’s negative free cash flow at three of the four largest AI spenders isn’t a temporary blip — it’s a multi-year bet that revenue conversion accelerates faster than depreciation and interest costs compound. So what for long-term investors: this isn’t a signal to abandon mega-cap tech, but it is a signal to differentiate. Companies funding AI investment out of existing cash flow, like Microsoft, carry a fundamentally different risk profile than those leaning on debt markets to chase the same opportunity. Watching credit spreads, not just earnings headlines, may be the more useful early-warning system for whether this capex cycle stays disciplined or starts cutting corners.