Joe Tsai took aim at the $500 billion attached to OpenAI's Stargate project—and the idea of investors building data centers "on spec."

"I start to get worried when people are building data centers on spec," said Alibaba Chairman Joe Tsai.

Alibaba-backed Ant Group said it used Chinese-developed chips to train AI models at a 20% lower cost and with similar results to what Nvidia Corp. chips for the