OpenAI is in early-stage discussions to run a secondary share sale that could value the artificial-intelligence company at about $500 billion, people familiar with the talks said. The tender offer would let current and former employees sell several billion dollars’ worth of stock ahead of any initial public offering, with existing investors including Thrive Capital expressing interest in buying the shares. A half-trillion-dollar price tag would mark a steep jump from the roughly $300 billion valuation OpenAI received in a SoftBank-led $40 billion primary fundraising announced earlier this year. Microsoft remains the company’s largest strategic backer. The negotiations come as OpenAI reports rapid operating momentum. The company expects its ChatGPT service to reach about 700 million weekly active users this week, up from 500 million in March and roughly four times the level of a year ago. Paying business customers have risen to about 5 million. OpenAI has doubled revenue in the first seven months of 2025 to an annualized pace of $12 billion and is aiming for $20 billion by year-end, according to a source cited by Reuters. The proposed share sale would give employees liquidity while underscoring investor demand for assets tied to generative-AI growth.