Sierra Secures $950 Million in Series E Funding, Valuation Reaches $15.8 Billion

Enterprise AI startup Sierra, co-founded by OpenAI board chairman Bret Taylor and former Google executive Clay Bavor, has successfully raised $950 million in a Series E funding round. According to ChainCatcher, the company's post-investment valuation now stands at $15.8 billion. The funding round was led by Tiger Global and Alphabet's venture capital arm, GV, with participation from existing investors such as Benchmark, Sequoia, and Greenoaks. Sierra specializes in providing AI customer service agent products designed to automate customer service and support scenarios for enterprise clients. The company has achieved an annual recurring revenue of $150 million within eight quarters. Bret Taylor noted that Sierra operates using a 'model group' approach, combined with its proprietary fine-tuning layer, to deliver AI agent services to enterprise customers. Previously, in October 2024, Sierra raised $175 million, with a valuation of $4.5 billion at that time.