Elon Musk may see Mark Zuckerberg as a rival, but the Meta chief never used to have any interest in the X owner, author says

• Elon Musk and Mark Zuckerberg's rivalry has peaked this year.
• However, an author who has profiled both CEOs says the rivalry has historically been one-sided.

Elon Musk and Mark Zuckerberg's rivalry may have peaked this year, but the two tech titans weren't always ready to throw punches.

That's according to Ben Mezrich, who wrote both the source material for "The Social Network" and the new book "Breaking Twitter." The latter chronicles Musk's chaotic acquisition of X, formerly Twitter.

Mezrich, who has profiled both tech bosses, told Business Insider in an interview that the rivalry between Musk and Zuckerberg had been relatively one-sided for some time.

"In all of my work I've done on Zuckerberg, I've never found any mention of him having any care or interest in Elon," he said. "I think Zuckerberg is more reacting to Elon."

In contrast, Musk has "this fascination, obsession, and competitive" relationship with Zuckerberg that "really goes deep," Mezrich said.

The tension between Musk and Zuckerberg culminated earlier this year when the Tesla CEO challenged Zuckerberg to a fight. Although agreed by both parties, the fight never took place — despite Musk once offering to drive to the Meta CEO's house.

Mezrich said Musk had wanted "to go head to head with Zuckerberg" for some time, and Zuckerberg was now engaging with the Tesla CEO.

"I really think it was somewhat one-sided, but now it seems to be something that Zuckerberg thinks about," he said.

"I definitely think he doesn't know what to make of Elon," he added. "I think he thinks that Elon is crazy."

Zuckerberg also took a public shot at Musk's business interests earlier this year when he launched Threads, a competitor to Musk's X. Threads had a sizable advantage from its link with Instagram and has been seen as one of the most serious challenges to X's user base.

The Tesla CEO also reportedly had Zuckerberg on his mind when he purchased X. Mezrich said Musk shouted, "fuck Zuck, fuck Zuck" when he first signed the papers to take over the platform.

Representatives for Zuckerberg and Musk did not immediately respond to BI's request for comment.