06:08 AM EDT, 10/02/2025 (MT Newswires) -- Microsoft ( MSFT )-backed (MSFT) OpenAI reached a $500 billion valuation after certain employees sold about $6.6 billion of shares, multiple news outlets reported Thursday, citing a person familiar with the matter.

The buyer group that bought the shares from current and former OpenAI employees included T. Rowe Price ( TROW ) , SoftBank, Thrive Capital, Dragoneer Investment Group, and Abu Dhabi's MGX, these reports said.

OpenAI had also authorized more than $10 billion of stock on the secondary market, the reports said.

SoftBank's involvement builds on its prior investment in OpenAI's $40 billion primary raise, the reports added.

OpenAI, SoftBank, Thrive Capital, Dragoneer Investment Group, MGX, and T. Rowe Price ( TROW ) did not immediately respond to MT Newswires' request for comment.