Sierra Annualized Revenue Run-Rate (ARR)
Dec 2024-May 2026
Annualized Run-Rate (USD M)
Updated at 2026-05
Sierra Channel Mix and Enterprise Customer Reach
| Metric | Figure | As of | Note |
|---|---|---|---|
| Voice Agents GA | Native phone support, sub-second latency | Feb 2025 | Adds voice channel alongside chat |
| Primary channel crossover | Voice surpasses text | Oct 2025 | Voice becomes the dominant channel on the platform (per Sacra) |
| Fortune 50 penetration | More than 40% | May 2026 | Claimed at the Series E; up-market enterprise posture |
| Customer size profile | ~50% have revenue over $1B | early 2026 | Large-enterprise concentration, not SMB volume |
| Named anchor verticals | Media, consumer hardware, fintech, insurance, healthcare, home security | 2024-2026 | SiriusXM, Sonos, ADT, Chime, Cigna, Nubank, Ramp, Rivian, Rocket Mortgage, Sutter Health, Wayfair |
Updated at 2026-05
Sierra Funding Rounds and Valuation Trajectory
| Round (date, lead) | Amount Raised | Post-Money Valuation | Notable Investors |
|---|---|---|---|
| Seed / Series A (2024-02, Benchmark) | $110M (cumulative) | ~$1B | Benchmark (lead), Sequoia, Ravi Gupta, Pat Grady |
| Series B (2024-10, Greenoaks) | $175M | $4.5B | Greenoaks (lead), Benchmark, Sequoia, Thrive Capital, ICONIQ |
| Series C (2025-09, Greenoaks) | $350M | $10B | Greenoaks (lead, per The Information), Sequoia, Thrive Capital, ICONIQ |
| Series E (2026-05, Tiger Global + GV) | $950M | $15.8B | Tiger Global (co-lead), GV (co-lead), Benchmark, Sequoia, Greenoaks |
| Total raised through Series E | ~$1.585B | n/a | Per Sacra; Sierra remains private |
Updated at 2026-05
Sierra Outcome-Based Pricing and Resolution Economics
| Pricing / outcome lever | How it works | Reported figure |
|---|---|---|
| Billable outcome | Sierra is paid only when an agent resolves a defined outcome (resolved case, saved cancellation, upsell, cross-sell, completed transaction) | Per resolved outcome, not per seat or per conversation |
| Escalation to human | When a case must be handed off to a human agent, in most cases there is no charge | Free in most cases |
| Blended / consumption fallback | Greeter and routing interactions, where outcome pricing fits poorly, can be billed on conversation count instead | Consumption-based for low-stakes routing |
| Containment rate (enterprise) | Share of interactions resolved by the agent without human handoff; the metric Sierra revenue is indexed to | ~70% reported by enterprise clients (per Sacra) |
| Customer satisfaction (CSAT) | Quality guardrail tracked alongside containment so resolution is not bought at the cost of experience | 4.5 / 5 or above (per Sacra) |
| Estimated year-one deal size | Custom-quoted via direct sales; Sierra does not publish list pricing | ~$200K to $350K+ (RUMORED, third-party estimate, not a Sierra disclosure) |
Updated at 2026-05
Sierra tau-bench Research and Product Cadence
| Date | Release | Significance |
|---|---|---|
| Sep 2023 | Company founded | Bret Taylor and Clay Bavor launch Sierra out of stealth-build |
| Feb 2024 | Commercial launch + Series A | Exits stealth at ~$1B; first customers (WeightWatchers, SiriusXM, Sonos, ADT) |
| Jun 2024 | tau-bench (text) | Open-source benchmark for tool-agent-user interaction (retail, airline); arXiv 2406.12045 |
| Aug 2024 | AgentOS | Runtime, observability, and guardrails for production agents |
| Feb 2025 | Voice Agents GA | Native sub-second phone-channel support added to the platform |
| 2025 | tau2-bench | Multimodal, knowledge-aware: voice evaluation plus large-document retrieval |
| 2025-2026 | Agent Outcomes (outcome-based pricing) | Billing tied to resolution / containment; aligns revenue with measured quality |
| 2026 | tau3-bench | Adds a banking domain and full-duplex voice evaluation across multiple real-time providers |
Updated at 2026-05
Sierra in AI Software
OpenAI
$PRIVATE
Largest AI lab by revenue. Approximately $13B annualized run-rate revenue (mid-2025) from a mix of ChatGPT consumer subscriptions, ChatGPT Enterprise / Team, the OpenAI API, and Microsoft Azure OpenAI revenue share. ChatGPT reaches roughly 800M weekly active users (late 2025). Builder of the GPT family (GPT-4o, GPT-4.5, GPT-5, o-series reasoning models) and Sora video. Microsoft is the dominant compute and distribution partner; SoftBank led the $40B March 2025 primary round at $300B.
