Bret Taylor's Sierra, which sells AI customer service agents, raised a $950M Series E led by Tiger and GV at a $15.8B post-money valuation, up from $10B in 2025
Artificial intelligence startup Sierra is raising nearly a billion dollars in a new funding round, CNBC has learned …
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Sierra Raises $950M at $15.8B Valuation for AI Customer Agents
Bret Taylor's AI customer service startup scores a massive Series E, jumping from $10B to $15.8B valuation.
Sierra just locked down a colossal $950 million Series E. Tiger and GV co-led the round, catapulting the AI customer service company to a $15.8 billion post-money valuation. That's a hefty jump from the $10 billion mark it hit in 2025.
The company, founded by former Salesforce co-CEO Bret Taylor, builds AI agents designed to handle customer service interactions. Nearly a billion dollars in fresh capital signals serious investor appetite for the AI agent space — particularly companies replacing traditional support workflows with autonomous systems.
Sierra's valuation leap of 58% between rounds is notable in a market where many late-stage startups struggle to maintain flat valuations. The round puts Sierra firmly among the most valuable private AI companies in the world right now.