InvestmentSeptember 9, 2026· Confirmed

Harvey raises $550M Series F at $15.5B valuation; acquires Guardrails AI

Scale: $550M Series F co-led by Diffusion and Lightspeed. Total raised >$1.5B. ARR >$400M. Simultaneously acquired Guardrails AI (agent security), fourth acquisition of 2026.
Vendors: Harvey AI
Significance: High
Confidence: Confirmed

Why this matters

This firm is putting capital behind AI, with Harvey AI in the stack. This is a high-significance signal for buyers benchmarking their panel.

Harvey closed a $550M Series F co-led by Diffusion and Lightspeed at a $15.5B valuation, up 41% from $11B in March. ARR reportedly exceeds $400M. Simultaneously acquired Guardrails AI, an agent security startup, marking Harvey's fourth acquisition of 2026. Also launched Harvey Tenet, its first post-trained open-weight model built on Moonshot's Kimi K3.

Scale / Terms: $550M Series F co-led by Diffusion and Lightspeed. Total raised >$1.5B. ARR >$400M. Simultaneously acquired Guardrails AI (agent security), fourth acquisition of 2026.
Significance: High
Source type: Trade Press

Vendors involved

Harvey AI

View primary source ↗

Elsewhere in the market