Billionaire tech executives Mark Zuckerberg and Elon Musk first suggested last month they'd be interested in clashing in a UFC-style cage fight—a seemingly absurd idea that's largely been laughed off as meaningless banter—but escalating tensions between the two and photos of them training with some of the world's top fighters has signaled a billionaire brawl could actually become a reality.

Key Facts

• The idea of a cage match was first posed by Musk over Twitter, where the Tesla CEO responded to a thread about Instagram's then-upcoming rival app Threads, saying, "I'm up for a cage match if he is lol."

• Zuckerberg responded the next day with an Instagram story showing a screenshot of Musk's tweet captioned "send me location"—a reference to a famous line from former UFC lightweight champion Khabib Nurmagomedov.