Arena
Arena evaluates AI models through comparisons and observations of how people use them in real tasks.
$200MSeries B
ParticipantAP
AMP PBC
Activity from announced rounds
All recorded activity
- Rounds participated in
- 3
- Confirmed lead rounds
- 1 1 roles undisclosed
- New companies
- 3 First participation on record · 0 follow-on
- Funding in participating rounds
- $1.4B 3 disclosed · full round size, not this investor’s share
By stage
By primary sector
By country
Rounds
3 in all activityRiver AI
Builds infrastructure for training and serving personally trainable AI agents
$1.1BSeed and Series A
LeadOpenRouter
Provides a unified API gateway enabling access, routing, and optimization across 400+ AI models for developers and enterprises
$113MSeries B
Role not disclosed