PALO ALTO – Artificial intelligence company Harmonic announced on Tuesday it has raised $120 million in a Series C funding round, catapulting the lab to a $1.45 billion valuation and “unicorn” status as it seeks to develop advanced mathematical reasoning systems.
The investment round was led by Ribbit Capital with significant participation from Sequoia Capital and Index Ventures. Kleiner Perkins also joined, along with new investor Emerson Collective.
Harmonic is focused on developing what it calls Mathematical Superintelligence (MSI), AI designed for complex reasoning with verified accuracy. The company said the new capital will accelerate the deployment of its flagship “Aristotle” model, which uses the formal verification programming language Lean4 to eliminate the “hallucinations” or factual fabrications common in other AI models.
The Aristotle model recently achieved a gold-medal level performance at the International Mathematical Olympiad, the world’s most prestigious math competition for high school students. It has since been made available via a public API.
“In its first few weeks, mathematicians and researchers have used Aristotle to accelerate progress and create novel discoveries,” the company said in a statement.
Harmonic’s CEO, Tudor Achim, said the model’s performance “offered an early glimpse into what Mathematical Superintelligence makes possible.”
“This funding allows us to advance that foundation even further and faster, while aggressively deploying Aristotle across industries where reliability is critical,” Achim said.
Nick Shalek, General Partner at lead investor Ribbit Capital, cited Harmonic’s “tremendous technical achievements” as the reason for the firm’s renewed investment.
The Series C round follows a $100 million Series B in July 2025 led by Kleiner Perkins and a $75 million Series A in September 2024 led by Sequoia Capital. The company is backed by Robinhood co-founder Vlad Tenev, who serves as its executive chairman.
“In even its early form, Aristotle already gives us a glimpse towards the better future we will all be in once advanced reasoning and formal verification fully merge,” Tenev said.