Nebius Just Revealed the Most Important Number That Could Change the AI Stock's Investment Thesis

Nebius Group reported a significant improvement in its payback period for Q2 contracts, falling to approximately 1 year and 10 months from a historical range of 2-3 years. The company signed four major AI cloud contracts averaging over $1 billion each with annual contract values above $20 million per megawatt, alongside 70% customer prepayments. While this demonstrates improving unit economics and operating leverage, risks remain including potential AI infrastructure oversupply and the company's continued massive capital requirements.