Nvidia shares were down 5% Monday, following a Wall Street Journal report detailing that the firm is in talks to provide a roughly $250 billion backstop for a massive OpenAI data-center project.

The report intensified investor concerns about circular financing in the artificial intelligence economy-and about the extent to which Nvidia is investing in its own customers, which in some cases need the chipmaker's financial backing to purchase its chips.

The data center, located in southern Ohio, is tied to a U.S. government initiative and would be developed by SB Energy, an energy subsidiary of SoftBank, the investment firm led by Japanese billionaire Masayoshi Son.

The $250 billion guarantee would cover the data-center lease and debt needed to fund its build-out, but not the Nvidia chips that would go inside it. Nvidia is also discussing a deal to finance the chip purchase for OpenAI, which could total $350 billion.

Chip stocks are broadly under pressure Monday. Shares of Advanced Micro Devices are down 8%. Oracle, which is developing several data centers for OpenAI, rose 4%, though its shares have fallen 50% since June.