The maker of ChatGPT overtook Elon Musk’s tech company with a $500 billion valuation following a recent share sale OpenAI has become the world’s most valuable startup, overtaking Elon Musk’s SpaceX, Bloomberg reported on Thursday. The milestone comes after current and former OpenAI employees sold around $6.6 billion worth of shares to investors in a secondary sale.Earlier this year, the ChatGPT maker was valued at around $300 billion compared to SpaceX’s $400 billion. However, the latest transaction has boosted the company’s valuation past $500 billion, according to a person familiar with the deal.The price tag boost comes as OpenAI has been in talks with Microsoft to restructure into a more traditional for-profit entity.Microsoft has been one of OpenAI’s closest partners and largest backers, investing billions of dollars into the company while expanding its own AI infrastructure. Microsoft CEO Satya Nadella expressed concern last month that advances in AI could make Microsoft’s core businesses obsolete as the company has already cut more than 15,000 jobs this year as part of a broader reorganization.OpenAI was founded in 2015 as a nonprofit research lab with the stated goal of developing AI “to benefit humanity as a whole.” Read more Musk becomes first person worth $500 billion – Forbes The group rose to prominence after the launch of ChatGPT in 2022, which was quickly adopted by millions of users. It has since released a series of increasingly advanced models, including GPT-5 in August 2025, while striking large-scale infrastructure agreements with partners such as Oracle and SK Hynix.Musk was one of the company’s co-founders but stepped down from the board in 2018. He has since accused OpenAI of abandoning its original nonprofit mission after taking billions in Microsoft funding. Last year, he filed a lawsuit seeking to block changes to the company’s structure, but a judge denied his request for an injunction, and the case remains ongoing. Meanwhile, Musk’s AI venture xAI has also sued OpenAI for alleged trade secret theft, which the ChatGPT maker has vehemently denied.