Nebius stock fell 10% on July 29 as rising credit-default-swap costs rippled through the AI cloud sector, signaling growing investor concern about the debt burden of companies racing to build out AI infrastructure.
Credit default swaps—insurance contracts that protect bondholders against default—have spiked to record levels across technology companies funding massive data center expansion. According to the Financial Times, investors now pay $215,000 annually to insure $10 million of debt for some major AI firms, up sharply from earlier in the year.
Nebius’ stock decline reflects a broader pattern. CoreWeave, another AI cloud infrastructure provider, dropped 36% over the past month as its five-year CDS spread now implies a 50% default probability, according to Yahoo Finance reporting on July 29. Nebius itself has fallen 43% over the same period, highlighting how credit market stress is translating directly into equity losses across the sector.
The surge in credit costs reflects a fundamental anxiety about the AI boom’s financing model. Major hyperscalers issued $182 billion in bonds in 2026 to fund AI data centers and infrastructure, representing a 1,300% annual jump, according to reporting from July 16. Yet as capital spending accelerates, bond investors are demanding higher premiums to cover perceived default risk.
Fitch, the ratings agency, warned on July 28 that an AI-related market correction is emerging as a major global credit risk. The firm cited the concentration of debt issuance, the unproven returns on massive capex, and refinancing challenges as key concerns. This warning came just as Nebius’ own CDS spreads widened, pushing the stock lower alongside peers.
Notably, Nebius had raised $775 million in secured debt financing just two weeks earlier on July 17, backed by customer contracts including $40 billion in committed revenue. The timing underscores the urgency with which AI infrastructure companies are locking in funding before credit conditions tighten further. The stock had surged 18.8% just days prior after Nvidia disclosed a 9.3% stake, but that momentum reversed as credit concerns took center stage.
The broader credit market stress reflects what bond investors see as a fundamental mismatch: AI companies are borrowing heavily based on future revenue expectations, yet the returns on these massive infrastructure investments remain uncertain. CoreWeave’s experience offers a cautionary precedent: its CDS spreads had jumped more than 53% between October and November 2025 amid similar concerns about profitability and refinancing risk.
Nebius is scheduled to report Q2 earnings on August 12, which could provide clarity on revenue growth and cash burn rates. Until then, credit markets are pricing in elevated risk, and equity investors are following suit. The company’s recent $775M debt deal was meant to fund AI cloud expansion, but rising borrowing costs could pressure margins and returns on that capital deployment.
Sources
- Yahoo Finance — Nebius stock drop and CoreWeave CDS default probability, July 29, 2026
- Financial Times — Record CDS costs for major AI firms, July 27, 2026
- 247wallst.com — Hyperscaler bond issuance data for 2026, July 16, 2026
- Reuters — Fitch warning on AI market correction as credit risk, July 28, 2026
- Nebius official newsroom — $775M secured debt financing announcement, July 17, 2026
