Sublime Security Raises $150M Series C to Expand Agentic AI Email Defense

Why It Matters

The funding fuels rapid scaling of autonomous email security, a segment under pressure from rising phishing and ransomware threats, and underscores investor confidence that AI‑driven defenses can outpace legacy solutions.

Deal Summary

Sublime Security announced a $150M Series C on 2025-10-28 led by Georgian to accelerate its agentic AI email security platform. New investors Avenir and 01A joined, alongside existing backers Index Ventures, IVP, Citi Ventures, and Slow Ventures.