Bret Taylor’s AI Startup Sierra Valued at $4.5 Billion

Sierra Technologies Inc., the artificial intelligence startup founded by OpenAI Chairman Bret Taylor and former Alphabet Inc. executive Clay Bavor, has raised $175 million in a financing round that values the company at $4.5 billion.

The deal represents a major valuation jump for the company, which was worth nearly $1 billion earlier this year.

Bret Taylor

Photographer: Nathan Laine/Bloomberg

Taylor, previously the co-chief executive officer of Salesforce Inc., said in an interview on CNBC Monday that while the funding environment in the industry seems “frothy,” AI’s promise justifies the outlays. “With the benefit of hindsight, it will probably be warranted,” he said, comparing ...