speaks at the Tesla Giga Texas manufacturing "Cyber Rodeo" grand opening party on April 7, 2022 in Austin, Texas. - Tesla welcomed throngs of electric car lovers to Texas on April 7 for a huge party inaugurating a "gigafactory" the size of 100 professional soccer fields. (Photo by SUZANNE CORDEIRO / AFP) (Photo by SUZANNE CORDEIRO/AFP via Getty Images)CEO of Tesla Elon Musk says he confronted fellow billionaire Bill Gates about whether he was shorting Tesla’s stock. Musk is seen here at the Tesla Giga Texas manufacturing “Cyber Rodeo” grand opening party on April 7, 2022.

Bill Gates has been accused by Musk of shorting him.

The CEO of the electric carmaker admitted on Friday that he asked Gates if he was short-selling shares. When investors short a stock, they bet that the price will fall.

Musk said that he asked Gates if he still had half billion short against him, because he heard that Gates still had a problem.

He was responding to a question on whether a screen grab of a purported text conversation between two billionaires was real.

I didn't leak it to NYT, said the chief. They must have gotten it through friends.

In the text exchange, which couldn't be independently verified by CNBC, Musk asked Gates if he still had a short position against the company.

Gates said he hadn't closed it out. I would like to talk about philanthropy.

Musk shot back, "Sorry, I cannot take your philanthropy on climate change seriously when you have a massive short position against the company doing the most to solve climate change."

When contacted by CNBC, a person for Bill Gates was not available.

Gates told Kara Swisher last year that the work done by Musk is one of the greatest contributions to climate change anyone has ever made. underestimating Elon is not a good idea.

Gates said that whatTesla was doing was easy, like passenger cars.

He said that we were not doing enough on the hard stuff. We have to work on the two-thirds.

If all you pay attention to is the short-term metrics, not the green premiums, then you miss out on what is the longest lead time.

The two men have had disagreements before.

I wonder why Bill Gates decided to go with the Taycan instead of aTesla when he revealed that he bought himself an all-electric car in 2020.

Musk said that his conversations with Gates have been disappointing.

Musk speculated on the possibility of Gates shorting his company's stock. Gates told CNBC last year that he doesn't talk about his investments but that he should be proud of what he has done.

In a February 2021 interview, Gates said that he wished he had been more on the long side of the company.

CNBC's Todd Haselton and Ryan Browne contributed to the report.