OpenAI is close to finalizing a $40 billion (¥6 trillion) funding round led by SoftBank Group — with investors including Magnetar Capital, Coatue Management, Founders Fund and Altimeter Capital Management in talks to participate, according to people familiar with the matter.

Magnetar Capital — an Evanston, Illinois-based hedge fund — could contribute up to $1 billion, according to multiple people, all of whom asked not to be identified because the information is private.

The artificial intelligence developer’s funding round would be the largest of all time, according to data compiled by research firm PitchBook. The deal is set to value the company at $300 billion including dollars raised — almost double the ChatGPT maker’s previous valuation of $157 billion from when it raised money in October.