Investor confidence that AI will generate enough revenue to support data centers’ heavy debt loads is weakening, and bonds financing some major U.S. projects have fallen sharply. According to ChainCatcher, the Financial Times reported that some bonds funding data centers for Meta, Nvidia and Oracle have dropped below face value.

Bonds issued by CoreWeave, an Nvidia-backed cloud infrastructure provider, have fallen below 80 cents on the dollar, a level typically considered distressed. Their yields approached 15% on Thursday. CoreWeave shares fell 17% this week, while rival Nebius dropped 18%; Nvidia lost about $270 billion in market value over the past week.

Ludovic Subran, chief investment officer at Germany’s Allianz, called the situation a “Darwinian moment” for data-center bonds, saying projects with weaker credit profiles would face a test of survival. He said power supply constraints and construction delays were widening credit spreads and that markets had previously been too optimistic in pricing the risks of enforcing data-center debt.

Concerns center on the gap between AI infrastructure investment and future revenue. OpenAI postponed its IPO until next year, while Anthropic’s quarterly sales growth slowed, adding to doubts about the sustainability of AI sector growth.

Gartner estimates that 80% of new cloud providers may not remain independent by 2030. The research firm says AI data-center owners would need to generate $8.5 trillion in revenue by the end of 2030 to cover capital and financing costs and earn a reasonable return. Consumer and business spending on AI services is expected to reach no more than $3.6 trillion by then, potentially leaving more than $4 trillion in assets at risk of impairment by 2032.

Some U.S. regions are tightening restrictions over data centers’ water use, noise and air pollution, while delays in power supply approvals are also holding up projects. Investors are wary of circular financing, in which companies in the sector finance one another. Nvidia CEO Jensen Huang said on Thursday that he did not believe CoreWeave needed a backstop from Nvidia, adding that CoreWeave’s cost of capital was falling and its operating position was improving.