Markets
CROSS-CATEGORY: $1B+ Deployed Into AI Agent Infrastructure in 10 Days — Sierra, CopilotKit, Judgment Labs Signal New Stack Layer
Between May 4-12, three companies raised $1B+ collectively to build different layers of the AI agent stack: Sierra ($950M, agent runtime for enterprises), CopilotKit ($27M, agent-to-UI protocol), and Judgment Labs ($32M, agent evaluation/quality). Together they define an emerging 'agent infrastructure' stack: build agents (Sierra), connect them to UIs (CopilotKit), measure if they work (Judgment Labs). This mirrors the 2015-2018 cloud infrastructure buildout (compute → orchestration → monitoring) but compressed into weeks. For builders: the agent stack is crystallizing — pick your layer.
↳ Follow the thread