The number of winning AI stocks may narrow down.

CNBC’s Jim Cramer suggested that after months of generally comfortable profits for some artificial intelligence companies, their performance could start to decline, and he expressed concern about OpenAI’s ability to pay for the billions of dollars it will spend on infrastructure.

“In an environment like this, we probably need to start diversifying into other growth areas in time to sideline all of the King’s horses and all of the King’s men,” he said. “Maybe OpenAI will be made public, and Humpty Dumpty won’t go down significantly, but until then we need to keep an eye on it.”

OpenAI has contracts worth hundreds of billions of dollars with many of its technology peers, and Cramer suggested the company may need to borrow money to meet its obligations. He said OpenAI CFO Sarah Friar’s recent comments were concerning. At an event earlier this week, Frier surprised investors by floating the idea that OpenAI could use governments as a backstop to meet its commitments — even though Frier later clarified that OpenAI is not currently seeking government funding.

So far, much of AI’s development has been supported by cash, not debt, Kramer said. But he stressed that debt financing is riskier than cash and makes companies more vulnerable. He also warned that the OpenAI issue could spread across the industry because the company works with so many companies in the space. He likened the situation to the rise of American railroads, with some companies going bankrupt after borrowing heavily. He said he wasn’t suggesting OpenAI would go bankrupt, but “I hope they slow down a little bit.”

Kramer proposed that OpenAI enter the burgeoning IPO market to raise billions of dollars to “clear the waters.” He also said he expects speculative tech stocks to subside, with “profits from miners, not just the guys making NVIDIA picks and AMD shovels.”

“I declare that the rest of this year is a time to invest with profits, not with magic,” Kramer said. “And when that happens, there will be far fewer winners and far more losers.”

OpenAI did not immediately respond to a request for comment.

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Disclaimer CNBC Investing Club Charitable Trust owns shares of Nvidia.