Antithesis raises $105M at $525M valuation as AI code floods the zone

Antithesis, a software-testing startup based in Tysons Corner, Virginia, has raised $105 million at a $525 million post-money valuation. The company is now considering yet another funding round as demand for its simulation platform keeps growing. What Antithesis actually raised, and from whom The Series A closed on December 3, 2025. Jane Street, the quantitative trading firm, led the round. Jane Street is also one of Antithesis’s major customers. The new valuation marks a big step up from the company’s last raise. In 2024, Antithesis came out of stealth after a $47 million seed round at a $215 million valuation. Total funding raised by the company now exceeds $180 million. Annualized recurring revenue has grown more than 12 times over the past two years and now sits at approximately $10 million. The $525 million price tag lands at a little over 50 times that recurring revenue. The fresh capital will go toward three buckets: expanding engineering, building out the platform’s autonomy features, and scaling sales and marketing. That go-to-market push spans North America, Europe, and Asia. The product is also available through the AWS Marketplace. A flight simulator for code Antithesis...