Bret Taylor, chairman of the board of directors of OpenAI, attends the annual Allen and Co. Sun Valley Media and Technology Conference at the Sun Valley Resort in Sun Valley, Idaho, on July 8, 2025.
David A. Grogan | CNBC
Bret Taylor’s artificial intelligence startup Sierra has just joined an exclusive club: The company sports a new $10 billion valuation after raising $350 million in fresh capital.
Sierra is one of just a handful of AI startups, including OpenAI, Anthropic, xAI, Safe Superintelligence and Thinking Machines that are valued at or above $10 billion.
Investors are pouring money into this competitive group of companies in the hopes that they’ll eventually hit the public markets.
Taylor is the chairman of OpenAI’s board, and previously served as co-CEO of Salesforce alongside Marc Benioff. Taylor co-founded Sierra in 2023. The company builds and implements AI agents for customer service. AI agents can carry out tasks autonomously on behalf of their users.
Shares of Salesforce fell 5% Thursday after the company reported weak guidance and concerns lingered about how AI is affecting software companies.
Sierra said its agents are already being used by “hundreds of millions of people” to help with tasks like refinancing homes, ordering lunch, delivering furniture, understanding insurance deductibles and fixing technology, among other things.
Greenoaks led Sierra’s latest funding round, the company said. Its valuation more than doubled from its most recent raise in October.
“We’re in this for the long term,” Sierra said in a blog post on Thursday.
The company said it will use its fresh funding to invest in its platform and focus on domestic and international expansion.
Sierra’s funding follows a flurry of other major AI raises in Silicon Valley. Earlier this week, Anthropic announced it had closed a $13 billion funding round at a $183 billion post-money valuation.
WATCH: Sierra co-founder Bret Taylor on AI agents’ role in an evolving global landscape
