OpenAI goes big and raises $6.6 billion.

OpenAI is now one of the richest private companies in the world after successfully raising $6.6 billion in its latest funding round at a valuation of $157 billion.

“Every week, more than 250 million people around the world use ChatGPT to improve their work, creativity and learning,” the company wrote in its announcement. “The new funding will allow us to double down on our leadership in cutting-edge artificial intelligence research, increase computing power, and continue building tools that help people solve complex problems.”

Existing backers such as Thrive Capital, Khosla Ventures and Microsoft are joined by newcomers SoftBank and Nvidia. Apple, which had previously been in talks to invest, pulled out earlier this week.

The funding news comes as OpenAI is considering restructuring its core business from a for-profit model to a for-profit model to make itself more attractive to investors. “We remain focused on creating artificial intelligence that benefits everyone, and we are working with our board of directors to ensure we are best positioned to succeed in our mission. This non-profit organization is central to our mission and will continue to exist,” an OpenAI spokesperson told Reuters at the time.

The investment round also comes at a time when OpenAI is struggling to retain top talent. Since last November, when the board of nonprofit OpenAI unsuccessfully tried to oust CEO Sam Altman from the company, a steady stream of researchers, founders and executives have resigned. Researchers Jan Leike and Ilya Sutskever quit in May to protest the company’s disregard for safety regulations in favor of selling “brilliant products.” At the end of September, technical director Mira Murati resigned, and research scientist Bob McGrew and senior scientist Barrett Zof quickly followed suit.

According to a Reuters report, OpenAI Chief Financial Officer Sarah Friar told employees that the company would offer to buy back their shares at a new valuation. Some employees were allowed to cash out their shares earlier this year at OpenAI’s previous valuation of $86 billion. As part of the proposed restructuring plan, Altman could receive up to $150 billion in capital, making him one of the richest people on the planet.