Sierra
SI
Sierra AI provides an AI agent platform for customer service. Businesses use it to automate and assist support interactions while following company policies and tone. The platform connects to customer support systems and can route conversations to human teams when needed.
Founded by Bret Taylor (Co-founder & CEO), Clay Bavor (Co-founder)
Blended valuation$15.2B$15B secondary
Valuation history
Weekly blended valuation with priced funding rounds marked on the timeline.
$17.1B
blended valuationfunding round
Dec 26, 2022$0Oct 5, 2026
All rounds
6 funding rounds, newest first.
| Round | Announced | Raised | Post-money |
|---|---|---|---|
| Series E | May 4, 2026 | $950M | $15.8B |
| Series D | Sep 4, 2025 | $350M | $10B |
| Series B | Oct 28, 2024 | $175M | $4.5B |
| Growth | Feb 13, 2024 | $110M | $1B |
| Series B | Jan 1, 2024 | $85M | $1.1B |
Join Legion to view all 6 rounds.Sign in to Legion
Investors
10 investors across all rounds.
- GRGreenoaks
- BEBenchmark
- SCSequoia Capital
- COConviction
- GVGoogle Ventures
- ICICONIQ Capital
- SASV Angel
- TCThrive Capital
- TGTiger Global Management
- BCBenchmark Capital Holdings
Secondary market activity
Recent buy and sell interest for Sierra shares on the secondary market.
| Kind | Implied valuation | Price / share | Date |
|---|---|---|---|
| $16.3B | — | Sep 29, 2026 | |
| $11.6B | $60.00 | Sep 23, 2026 | |
| $11.6B | $60.00 | Sep 22, 2026 |
Invest in the private markets on Legion
Registered users see full trading activity, every investor, rankings, and live deals.
Data as of Oct 15, 2026. Valuations are estimates blended from primary and secondary-market signals — not investment advice.