Musk and Altman reignite feud over AI leadership, trading accusations

The feud between Musk and Altman traces back to OpenAI's founding in 2015 as a nonprofit AI research lab. At the time, Musk and Altman partnered with other cofounders, with Musk pledging roughly $1 billion（約1600億円） in funding over several years. However, when Musk believed OpenAI was falling behind in the AI race, he attempted to take control in 2018—an offer that Altman rejected. Musk subsequently left the board and stopped funding, creating a rift that has defined their relationship for over six years.

After ChatGPT's 2022 release transformed OpenAI into a market leader, the feud escalated to litigation. Musk's 2024 lawsuit claimed Altman had transformed OpenAI into an opaque web of for-profit entities, betraying the original mission. OpenAI countered that Musk only turned hostile after his takeover bid failed. Though a jury dismissed Musk's case in May on statute-of-limitations grounds, the underlying tension persists.

Today, both men are using public platforms to promote their competing AI visions to investors. Musk's SpaceX went public in June with a record-setting IPO partly on the strength of its rebranded SpaceXAI division, which acquired xAI in 2023. OpenAI filed confidentially for its own IPO the same month. The recent tit-for-tat product launches—GPT-5.6 Sol and Grok 4.5 released within days of each other—and public accusations appear designed to sway investor confidence. Musk's appeal of the dismissed lawsuit remains pending, suggesting the legal chapter of the feud is far from closed.