Current and former OpenAI staff are preparing to sell nearly $6bn worth of shares to investors, including SoftBank Group, Thrive Capital, and Dragoneer Investment Group.

The secondary share sale would raise OpenAI’s valuation to around $500bn, up from $300bn, reflecting the company’s rapid revenue growth and fierce competition in the artificial intelligence sector.

Bloomberg, which first reported the move, said discussions remain at an early stage and the final size of the sale could change. SoftBank, Thrive, and Dragoneer, all existing OpenAI investors, declined to comment.

The deal would come alongside SoftBank’s leading role in OpenAI’s $40bn primary funding round.

Backed by Microsoft, OpenAI has seen its revenues surge, doubling in the first seven months of 2025. It is currently running at an annualized $12bn and is projected to reach $20bn by year-end, according to Reuters reporting earlier this month.

ChatGPT, its flagship product, has also seen explosive growth, with weekly active users rising to about 700 million in August, up from 400 million in February.

The prospective sale underlines investor demand for exposure to leading AI firms, as companies race to secure talent and market dominance in one of the world’s fastest-growing industries.