Elon Musk is all about robots. He has likened his self-driving Tesla cars to “robots on wheels.” As for the robots on legs, he has grand plans for eventually selling a humanoid robot named Optimus. When he showed the prototype last year, Optimus failed to impress artificial intelligence experts and investors. But that hasn’t deterred Musk, and at Tesla’s Investor Day this week, the billionaire showed off the latest version and made a grand prediction: Humanoid robots could eventually outnumber humans.

“You could sort of see a home use for robots, certainly industrial uses for robots, humanoid robots,” Musk said. “I think we might exceed a one-to-one ratio of humanoid robots to humans. It’s not even clear what an economy is at that point.”

Optimus is still a long way away from leading the robot revolution. When Musk first introduced it to the public in 2021, it turned out to be a human in a robot suit rather than an actual prototype. In 2022, Optimus had to be wheeled into Tesla’s A.I. Day. In his presentation this year, Musk showed videos of the new Optimus, which appears to be walking on its own.  

Musk isn’t the only one to point out a looming economic disruption because of the A.I. and robot disruption. Robots have already been rolled out in factories to replace jobs that human beings used to do, and last year saw record demand for automation as companies struggled to hire workers. But recent A.I. developments might only accelerate that switch. IBM CEO Arvind Krishna recently said that he believed clerical white-collar work would be replaced by A.I., and that robots could even help with a future labor shortage as the population ages. And Kai-Fu Lee, an A.I. venture capitalist, said in 2019 that the technology would replace 40% of jobs within the next 15 years, including both white-collar and blue-collar work. 

Tesla’s website describes the humanoid “Tesla bot” as one that could accomplish “performing unsafe, repetitive, or boring tasks.” But Musk’s vision for what robots can be goes well beyond that. Musk said Wednesday he anticipates that humanoid robots “will probably be worth significantly more than the car side of things long-term,” as their uses will be wide-ranging. In the past, he has also mentioned robots being used as a “buddy.”

While Musk is bullish about his own robots, he said on Wednesday that underlying technology for A.I. still “stresses” him out.  

“It’s quite dangerous technology. I fear I may have done some things to accelerate it,” he said. 

Musk was a cofounder of ChatGPT’s parent company, OpenAI, but left the company after only a few years. He has since called the chatbot tool “concerning” and criticized OpenAI for contradicting its purpose of being an open-source nonprofit “counterweight to Google,” accusing it of  being a “closed source, maximum profit company.”

The world’s second-richest man is now believed to be assembling a project that would rival OpenAI.

Tesla did not immediately return Fortune’s request for comment.