Harmonic
AI lab building mathematical superintelligence with verifiable reasoning that eliminates hallucinations.
- Founded
- 2023
- Headquarters
- Palo Alto, CA
- Latest Round
- Series C
- Est. Valuation
- ~$1,450M
Investment Thesis
Harmonic is an AI lab leading the development of Mathematical Superintelligence (MSI) — AI systems capable of formal mathematical reasoning with verifiable proofs that eliminate hallucinations. The company's flagship Aristotle model achieved gold-medal level performance at the International Mathematical Olympiad, the world's most prestigious math competition.
Co-founded in 2023 by Tudor Achim (CEO) and Vlad Tenev (CEO of Robinhood), Harmonic has rapidly become one of the most well-funded AI labs globally. The company raised $75M in a Series A led by Sequoia Capital in September 2024, followed by a $100M Series B led by Kleiner Perkins in July 2025 at a ~$900M valuation, and a $120M Series C led by Ribbit Capital in November 2025 at a $1.45B valuation.
Current AI systems excel at pattern matching and language but fundamentally struggle with formal reasoning, mathematical proof, and the kind of rigorous logical thinking that underpins science and engineering.
Harmonic is building AI systems purpose-built for mathematical reasoning and formal verification, pursuing a path to superintelligence through provable logic rather than statistical language patterns — an approach that could unlock breakthroughs in math, physics, and software verification.
The formal verification and automated theorem proving space has seen landmark results recently (AlphaProof, Lean ecosystem growth), validating that AI-assisted mathematics is reaching an inflection point.
Advances in reinforcement learning and search combined with growing formal math corpora (Lean's Mathlib) have created the conditions for AI systems that can reason about abstract structures — not just predict the next token.
Funding & Investors
Headcount Growth
Latest News
Harmonic Builds Momentum Towards Mathematical Superintelligence with $120 Million Series C
BusinessWire
Harmonic Raises $100 Million Series B to Accelerate Development of Mathematical Superintelligence
BusinessWire
Robinhood CEO's math-focused AI startup Harmonic valued at $1.45 billion
Yahoo Finance