The company at the heart of the artificial-intelligence revolution, OpenAI, just raised money at a $300 billion valuation, as the publicly traded AI stocks advanced on Tuesday.

Sam Altman’s OpenAI has closed a new $40 billion fundraising deal that almost doubles the firm’s valuation and cements it as one of the most valuable private companies in the world.

Houston-based Chevron Corp. (NYSE: CVX) has sold a 70% stake in its East Texas gas assets for half a billion dollars. TG Natural Resources LLC, also based in Houston, bought the majority stake for $525 million. The company paid $75 million in cash and $450 million as a capital carry to fund development in the Haynesville Shale.

Chevron has agreed to sell 70% interest in its East Texas gas assets for $525 million, as part of the U.S. energy company’s strategy to optimize its portfolio.

Chevron has finalized a $525 million deal to sell a 70% stake in its East Texas natural gas assets to TG Natural Resources LLC, backed by Tokyo Gas and Castleton Commodities.