Harmonic raises $120 million Series C. PALO ALTO - Harmonic, an artificial intelligence lab leading the development of Mathematical Superintelligence (MSI), has raised $120 million Series C funding round at a $1.45 billion post-money valuation. This round is led by Ribbit Capital with significant participation from Sequoia Capital, Index Ventures, Kleiner Perkins and Emerson Collective as a new investor. Robinhood CEO Vlad Tenev is a founder of the company. Harmonic's flagship Aristotle model recently achieved gold-medal level performance at the International Mathematical Olympiad, considered the most prestigious mathematical competition in the world, and is now available to the public. Unlike other models, Aristotle makes use of formal verification using Lean4 to ensure accuracy and eliminate hallucinations. In the first few weeks since its API beta launch, Aristotle has already been used by mathematicians and researchers to accelerate progress and create novel discoveries. Last week, Harmonic rolled out major upgrades, including support for plain English input (in addition to native Lean4), automated lemma generation, and a streamlined terminal interface. "Aristotle's gold-medal performance at the IMO offered an early glimpse into what Mathematical Superintelligence makes possible with advanced reasoning and formal verification together in a single system," said Tudor Achim, CEO of Harmonic. "This funding allows us to advance that foundation even further and faster, while aggressively deploying Aristotle across industries where reliability is critical." "The Harmonic team is achieving extraordinary success in showing how MSI can accelerate progress in mathematics and other quantitative fields, and Aristotle, even in its early form, already gives us a glimpse towards the better future we will all be in once advanced reasoning and formal verification fully merge," said Vlad Tenev, Co-Founder and Executive Chairman of Harmonic. "Ribbit's renewed investment reflects the tremendous technical achievements Harmonic has already made," said Nick Shalek, General Partner at Ribbit Capital. "We're proud to deepen our partnership as Aristotle continues to demonstrate what Mathematical Superintelligence can achieve in the real world." Harmonic previously raised $100 million in its July 2025 Series B funding round led by Kleiner Perkins, and $75 million in its September 2024 Series A, which was led by Sequoia Capital and included significant participation from Index Ventures. Additional backers include Paradigm and Era Funds.

Harmonic raises $120M in Series C funding. Harmonic, a Palo Alto, CA-based artificial intelligence lab developing a mathematical superintelligence (MSI), raised $120M in Series C funding, at $1.45 Billion valuation. The round was led by Ribbit Capital with participation from Sequoia Capital, Index Ventures, Kleiner Perkins and Emerson Collective as a new investor. The company intends to use the funds to expand operations and its development efforts. Founded in 2023 and led by CEO Tudor Achim, and Vlad Tenev, Harmonic is an artificial intelligence company developing mathematical superintelligence (MSI). Its flagship Aristotle model recently achieved gold-medal level performance at the International Mathematical Olympiad, and is now available to the public. The model makes use of formal verification using Lean4 to ensure accuracy and eliminate hallucinations. In the first few weeks since its API beta launch, Aristotle has already been used by mathematicians and researchers to accelerate progress and create novel discoveries. The company says that it rolled out major upgrades, including support for plain English input (in addition to native Lean4), automated lemma generation, and a streamlined terminal interface. Harmonic previously raised $100M in its July 2025 Series B funding round led by Kleiner Perkins, and $75M in its September 2024 Series A, which was led by Sequoia Capital and included significant participation from Index Ventures. Additional backers included Paradigm and Era Funds.

Harmonic AI raises $120M at $1.45B valuation to advance mathematical reasoning. Artificial intelligence for formal mathematical reasoning startup Harmonic AI Inc. announced today that it has raised $120 million in new funding on a $1.45 billion valuation. The funding is intended to accelerate its momentum in developing an advanced mathematical reasoning model that eliminates hallucinations, a common situation in which AI models make up erroneous answers. The company was co-founded in 2023 by Vlad Tenev, chief executive of Robinhood Markets Inc. Its main offering is Aristotle, an AI engine that specializes in formal mathematical reasoning. The engine uses the Lean 4 proof assistant, a proof assistant that allows users to write mathematical definitions, theorems and proofs in a way that can be checked for correctness by a computer, to translate natural-language math problems into formally verifiable proofs. The company's approach is focused on mathematical superintelligence, AI with reasoning capabilities that match or exceed humans. The methodology involves the use of synthetic data generation for training that, instead of relying on web-scraped data, autonomously generates formal problem-proof pairs, which enable recursive self-improvement. Essentially, the AI model can train itself through a "self-play loop" to scale its capabilities, working from simple exercises toward solving advanced theorems. Aristotle recently achieved a gold-medal level performance at the International Mathematical Olympiad, considered the most prestigious mathematical competition in the world and is now available to the public. More recently, Harmonic released an application programming interface for Aristotle that has already been used by mathematicians and researchers to accelerate progress and create novel discoveries. The company also rolled out major upgrades last week, including support for plain English input (in addition to native Lean4), automated lemma generation and a streamlined terminal interface. "Aristotle's gold-medal performance at the IMO offered an early glimpse into what Mathematical Superintelligence makes possible with advanced reasoning and formal verification together in a single system," said Harmonic Chief Executive Tudor Achim. "This funding allows us to advance that foundation even further and faster, while aggressively deploying Aristotle across industries where reliability is critical." The Series C funding round was led by Ribbit Capital Management, with Sequoia Capital Operations, Index Ventures Management, Kleiner Perkins Caufield & Byers and Emerson Collective also participating. "The Harmonic team is achieving extraordinary success in showing how MSI can accelerate progress in mathematics and other quantitative fields and Aristotle, even in its early form, already gives us a glimpse toward the better future we will all be in once advanced reasoning and formal verification fully merge," said Tenev, who serves as Harmonic's executive chairman. The new funding follows previous raises of $100 million in Series B funding on a $900 million valuation in July and a Series A raise of $75 million in September 2024. Image: Harmonic. A message from John Furrier, co-founder of SiliconANGLE: Support its mission to keep content open and free by engaging with theCUBE community. Join theCUBE's Alumni Trust Network, where technology leaders connect, share intelligence and create opportunities. * 15M+ viewers of theCUBE videos, powering conversations across AI, cloud, cybersecurity and more * 11.4k+ theCUBE alumni - Connect with more than 11,400 tech and business leaders shaping the future through a unique trusted-based network. SiliconANGLE Media is a recognized leader in digital media innovation, uniting breakthrough technology, strategic insights and real-time audience engagement. As the parent company of SiliconANGLE, theCUBE Network, theCUBE Research, CUBE365, theCUBE AI and theCUBE SuperStudios - with flagship locations in Silicon Valley and the New York Stock Exchange - SiliconANGLE Media operates at the intersection of media, technology and AI. Founded by tech visionaries John Furrier and Dave Vellante, SiliconANGLE Media has built a dynamic ecosystem of industry-leading digital media brands that reach 15+ million elite tech professionals. Its new proprietary theCUBE AI Video Cloud is breaking ground in audience interaction, leveraging theCUBEai.com neural network to help technology companies make data-driven decisions and stay at the forefront of industry conversations.