OREANDA-NEWS  American OpenAI, the developer of the GPT chatbot, has become the most expensive private company in the world after completing a deal on the secondary sale of shares to investors with an estimated value of $ 500 billion, CNBC writes.

The opportunity to sell their shares was given to the company's employees who had owned them for more than two years. In total, securities worth $6.6 billion were sold, while the permit provided for the sale of up to $10.3 billion.

The buyer of the shares was a consortium of investors, which included Thrive Capital, SoftBank, Dragoneer Investment Group, MGX and T. Rowe Price.

During the investment round completed in April of this year, OpenAI was valued at $300 billion.

OpenAI's current cost calculation makes it the most expensive private company in the world. Previously, SpaceX was considered such, estimated at $456 billion.