Anthropic's prospectus reveals a $42 billion net loss in 2025 despite 12x revenue growth to $4.6 billion. Heavy spending on computing and infrastructure drove costs, with $7.33 billion spent last year. The company plans to invest $51.8 billion next year for model training and infrastructure. Revenue concentration risk is highlighted, with nearly 25% from two clients lacking long-term contracts, posing significant valuation uncertainty despite strong operational growth.