Sam Altman Just Pulled Off a $500 Billion Win in His Feud With Elon Musk

When Elon Musk and Sam Altman co-founded OpenAI a decade ago, the idea was to build artificial intelligence that would benefit humanity. At the time, a small group of technologists framed the project as a nonprofit effort to make sure AI was safe.

Eventually, Musk left and started his own competing AI company. Since then, he’s taken every chance to criticize OpenAI and even sued to prevent it from becoming a for-profit company. Now Altman has something Musk doesn’t: the most valuable startup in the world.

On Thursday, Bloomberg reported that OpenAI closed a secondary share sale valuing the company at $500 billion. That makes OpenAI the world’s most valuable private company, overtaking—ironically—Musk’s SpaceX, which was last valued at around $400 billion. The OpenAI deal involved about $6.6 billion in employee shares sold to investors, including Thrive Capital, SoftBank, and T. Rowe Price.

That number—half a trillion dollars—doesn’t change Musk’s balance sheet. In fact, in the ultimate irony, on Wednesday, Musk became the first human with a net worth of $500 billion, according to Forbes. None of that, however, is from OpenAI stock.

Musk walked away from OpenAI in 2018 and gave up his stake. But as a measure of bragging rights, it’s hard to miss the symbolism: Sam Altman just pulled off a $500 billion win in his feud with Elon Musk. Sure, Musk is worth far more than Altman personally, but the fact that OpenAI just passed SpaceX is a big deal.

OpenAI’s founding

The story of the rivalry between the two men is complicated. Back in 2015, they believed AI would be one of the most powerful technologies ever invented, with the potential to help—or to harm—humanity. OpenAI was set up with a nonprofit structure in order to guard against the temptation to simply chase profit.

Musk left OpenAI’s board in 2018, citing conflicts with Tesla’s own AI efforts. Not long after, OpenAI began a shift from nonprofit into the unusual “capped profit” structure that would allow it to raise billions from Microsoft and others while still keeping the nonprofit in control.

That’s where the feud gets interesting. Musk accused OpenAI of abandoning its founding mission and becoming just another Silicon Valley startup chasing money. He’s repeatedly blasted Altman and the company on X (formerly Twitter), calling it reckless and dishonest.

Altman, for his part, rarely mentions Musk directly. He doesn’t have to. His work building OpenAI into the leading AI company is the louder statement.

Musk has a lot at stake

At the same time, Musk has spent the past two years trying to build a rival. His startup, xAI, is working on its own large language models to power what he calls “truthful AI.” He’s tied xAI closely to X, integrating its chatbot, Grok, into the platform.

Musk also filed a lawsuit against OpenAI and Altman, accusing them of turning the nonprofit into a for-profit venture in violation of its founding charter. He even sued Apple, alleging that it gave ChatGPT unfair preference in the App Store recommendations. There are a lot of feelings between these two men.

OpenAI may be the world’s most important company

It’s worth mentioning that OpenAI still hasn’t turned a profit. Running massive AI models costs staggering amounts of money, and the company is dependent on investors and customers like Microsoft to keep funding its growth. But the $500 billion valuation says something powerful about how investors view Altman’s company.

It also says something about Musk. For years, SpaceX held the title of the most valuable private company in the world. It’s also easily one of the most important in terms of the tech it is building, as well as the implications it has for national security.

SpaceX is an incredible success story—building reusable rockets, dominating satellite launches, and creating Starlink, a global communications network. That valuation is built on real revenue and real products. Now, however, SpaceX has been dethroned. And it has to hurt a little that the company that passed it is the one Musk helped start and then abandoned.

The broader story here is that AI has become the center of gravity in the tech world. Investors believe it will reshape entire industries, and they’re willing to bet half a trillion dollars on the company leading that charge.

It’s a battle for the future of computing

Still, the personal rivalry matters. Musk isn’t just another competitor—he’s a co-founder turned critic, suing to stop Altman’s plans while racing to build his own alternative. Altman, meanwhile, has emerged as the face of generative AI, striking deals, launching products, and now surpassing Musk in the only metric the tech world really keeps score by: valuation.

For Musk, the sting is sharper because the loss is symbolic. He doesn’t own OpenAI anymore. He can’t share in the financial upside. All he has is the lawsuit and the microphone of his social network.

For Altman, the win is equally symbolic. $500 billion doesn’t just buy bragging rights—it cements OpenAI’s place as the most important startup of the AI era.

And for everyone else, it’s a reminder that behind the world-changing technology are human egos, rivalries, and grudges. The future of AI isn’t just about chips, models, and data centers. It’s also about two men who once shared a mission, now locked in a feud, with the scoreboard tilting heavily in Altman’s favor.