Current and former OpenAI employees are in talks to sell nearly $6 billion worth of shares to investors led by SoftBank Group, according to Reuters. The secondary transaction would lift the Microsoft-backed artificial-intelligence developer’s valuation to roughly $500 billion, up from about $300 billion in the most recent staff tender earlier this year. Discussions remain preliminary and the size of the sale could still change, people familiar with the matter said. SoftBank, Thrive Capital and Dragoneer Investment Group—already investors in OpenAI—are among the parties considering the purchase. The move would add to SoftBank’s role in a separate $40 billion primary funding round it is organising for the company. A higher valuation would reflect the rapid uptake of OpenAI’s products. Reuters reporting shows the company doubled revenue in the first seven months of 2025, reaching an annualised run-rate of about $12 billion and projecting $20 billion by year-end. Weekly active users of ChatGPT have risen to roughly 700 million, up from 400 million in February. The prospective share sale follows last week’s release of GPT-5, an updated large-language model that drove a sharp jump in API traffic. Chief Executive Officer Sam Altman has said the firm expects to spend "billions of dollars" on new data-centre infrastructure to keep pace with demand.