Bret Taylor, co-founder and CEO of Sierra, speaking to CNBC at the World Economic Forum in Davos, Switzerland on Jan. 22nd, 2026. CNBC Artificial intelligence startup Sierra is raising nearly a billion dollars in a new funding round, CNBC has learned, as venture capital investors search for winners in an ongoing deal spree. The San Francisco-based company brought in $950 million in fresh capital at a $15.8 post-money valuation, led by Tiger and Google's GV. Benchmark, Sequoia, Greenoaks and other existing investors also participated. The startup was founded three years ago by OpenAI chairman and former Salesforce co-CEO Bret Taylor , with former Google executive Clay Bavor. Taylor was also chief technology officer at Facebook , and chairman of Twitter when Elon Musk bought the social media network. The Sierra founders met at Google, where Taylor was largely credited with helping create Google Maps and Bavor led virtual reality efforts and Google Labs.…