Sierra Raises $950M at $15.8B Valuation as Enterprise AI Agent Demand Surges

Summary

Sierra, the enterprise conversational AI company founded by Bret Taylor (OpenAI chairman, former Salesforce co-CEO) and Clay Bavor (former Google), raised $950 million in a round led by Tiger Global and Google's GV, pushing its valuation to $15.8 billion. The funding follows rapid ARR growth from $100 million in late November 2025 to $150 million by early February 2026 — a pace that places it among the fastest-growing enterprise SaaS companies on record. Client concentration is heavily in regula