In a late-night post Wednesday, the Tesla ( TSLA ) and SpaceX CEO claimed that Bezos had warned “everyone” to sell their shares in his companies if Vice President Kamala Harris wins the 2024 presidential election. Musk has made a big bet — seemingly successful — that President-elect Donald Trump will win, repeatedly claiming that the Harris administration will seek revenge against him.

“Just learned tonight at Mar-a-Lago that Jeff Bezos told everyone that @realDonaldTrump will definitely lose, so they should sell all their Tesla and SpaceX stock,” Musk wrote on X, the social media platform he owns, adding an emoji at the end.

“No. 100% not true,” Bezos said in a rare post on X. He has only posted on this platform four times in 2024, including writing a message earlier this month to congratulate Trump on his victory and a statement following the first assassination attempt on the then-Republican presidential candidate.

This is the latest shot fired in the competition between two leading technology companies, who are the richest and second-richest individuals in the world, according to the Bloomberg Billionaires Index. Musk's net worth has reached $331 billion after Tesla's stock surged following Trump's victory, and his xAI and SpaceX are said to be eyeing major value boosts. Bezos has a net worth of $226 billion, largely due to his stake in Amazon (AMZN).

Musk's SpaceX is a dominant force in the aerospace industry, while Bezos's Blue Origin is working to establish itself as a competitor. This week, NASA requested both companies to develop cargo landers to transport equipment to the Moon as part of its Artemis missions. The two companies and United Launch Alliance, a joint venture between Boeing (BA) and Lockheed Martin (LMT), will compete for national security space mission contracts over the next five years.

Blue Origin has previously opposed a contract that NASA awarded to SpaceX and sought to limit SpaceX's Starship launches, while Amazon's Kuiper has opposed plans to expand SpaceX's Starlink satellite network. In 2020, Musk called on the government to break up Amazon, complaining about its monopoly.