Sierra · 2026-05-04 · major
Sierra Raises $950M at $15B+ Valuation — Tiger Global, GV Lead Round for Bret Taylor's Enterprise Agent Platform
Sierra closes a $950M Series E at over $15B, led by Tiger Global and GV with Benchmark, Sequoia, and Greenoaks. The Bret-Taylor- and Clay-Bavor-founded enterprise agent platform claims 40%+ Fortune 50 penetration and ~$150M ARR after eight quarters.
Sierra closes a $950M Series E at $15B+, putting Bret Taylor's enterprise customer-experience agent platform on a $1B+ war chest.
Key specs
| Round size | $950M |
|---|---|
| Valuation | $15B+ |
| Arr early february2026 | $150M |
| Fortune50 penetration | 40%+ |
What is it?
Sierra builds AI agents that run end-to-end customer interactions for large enterprises — handling mortgage refinancing, insurance claims, order returns, fundraising, and similar voice/chat workflows. Co-founders Bret Taylor (OpenAI chair) and Clay Bavor announced the round in a joint blog post.
How does it work?
Sierra ships persistent agents that integrate into a company's CRM, support, and back-office systems and answer customers across phone, chat, and email channels. The post highlights deployment speeds — Nordstrom in 5 weeks, Cigna in 8 weeks, Singtel in 10 weeks — as the differentiator over a traditional services rollout. The new round is led by Tiger Global and Google Ventures, with Benchmark, Sequoia, and Greenoaks participating.
Why does it matter?
Sierra's $15B+ valuation and the $1B+ in cash it now has on hand make it one of the best-funded AI startups outside the frontier labs. Per CNBC, ARR was around $150M as of early February 2026, a pace the company says no traditional software firm has matched. Bret Taylor told CNBC an IPO is 'definitely in our future,' but the company plans to stay private for now.