Vlad Tenev

Vlad Tenev (born 1987) emigrated from Bulgaria as a child, studied mathematics at Stanford, and co-founded Robinhood with Baiju Bhatt in 2013, popularizing commission-free stock trading — and drawing lasting controversy over gamification and the 2021 GameStop trading halts. As CEO he has folded AI steadily into the brokerage, including Robinhood Cortex, an AI investing assistant launched in 2025.

Betting on provable AI

Tenev’s deeper AI conviction is Harmonic, the research lab he co-founded in 2023 with Tudor Achim to pursue what they call mathematical superintelligence. Announcing it publicly in June 2024, Tenev argued that hallucination is the core defect of large language models and that mathematics — humanity’s original tool for pinning down truth — is the fix: Harmonic’s models generate proofs formally verified in Lean, so answers are checked rather than trusted. The company raised funding at an $875 million valuation in 2025, released a consumer chatbot called Aristotle, and its system reached gold-medal performance on International Mathematical Olympiad problems.

Tenev has said Harmonic’s system now exceeds his own considerable mathematical ability and frames verified reasoning as the safest path to superintelligence — a contrarian position in a field racing toward ever-larger general models. Skeptics ask how far formal verification can stretch beyond mathematics into the messy domains where most AI harm occurs, and note that “hallucination-free” claims apply only within the proof system’s walls.