Nebius Group has emerged as one of the most closely watched names in the AI infrastructure market after its shares climbed roughly 40% in less than two weeks following a strong second-quarter performance. The rally reflects accelerating demand for AI computing capacity, but it also raises a more difficult question for investors: whether the company’s exceptional growth can continue quickly enough to justify its increasingly demanding valuation.

Revenue Growth Is Accelerating at an Exceptional Rate

Nebius reported second-quarter 2026 revenue of $582.3 million, up 454% from $105.1 million a year earlier and 46% from the first quarter. Revenue from its core Nebius AI cloud business reached $574.9 million, representing a 514% year-over-year increase and accounting for approximately 98% of group revenue.

The company also reported an annualized run-rate revenue of approximately $3 billion at the end of June, up 56% from the previous quarter. Four major AI cloud contracts signed during the quarter averaged more than $1 billion in total contract value, demonstrating that demand is increasingly coming from large enterprise and technology customers rather than only smaller AI developers.

These figures help explain the stock’s rapid appreciation. However, extraordinary revenue growth also creates elevated expectations. Any slowdown in contract signings, capacity deployment or customer utilization could have an outsized effect on market sentiment.

AI Capacity Expansion Comes With Heavy Capital Requirements

Nebius is aggressively expanding its infrastructure to capture the AI computing boom. The company raised its year-end 2026 contracted power guidance to 5 gigawatts and expects to deploy more than 1 gigawatt annually from 2027. Its expansion footprint now spans multiple markets, including the United States and Europe.

The strategy requires substantial investment. Capital expenditures reached approximately $5.7 billion during the first half of 2026, highlighting the capital-intensive nature of the AI cloud model. The company also announced a $5 billion convertible bond offering, increased from an initial $4.5 billion target, to finance data-center expansion and AI development.

While customer prepayments can finance 50% to 60% of capital expenditure on certain contracts, additional borrowing and potential equity dilution remain important considerations. The company’s total convertible debt is also becoming substantial, increasing the importance of future cash generation.

Is Nebius Still a Bargain After the Rally?

Nebius continues to present a high-growth profile, but the question of valuation has become more complicated following the recent surge. The company reiterated its 2026 revenue guidance of $3 billion to $3.4 billion, while its AI cloud adjusted EBITDA margin reached 50% in the second quarter, showing that operating leverage is beginning to emerge as capacity scales.

At the same time, competition among AI infrastructure providers is intensifying, while hyperscalers and other specialized cloud companies continue investing billions of dollars in computing capacity. Nebius must therefore convert its large customer commitments into actual revenue while maintaining attractive returns on the enormous capital being deployed.

For investors, the next stage of the story will depend less on whether Nebius can demonstrate rapid growth and more on whether that growth remains profitable and capital-efficient. Customer commitments, utilization rates, data-center deployment, cash flow and financing costs will be critical indicators. The recent rally has strengthened the growth case, but it has also reduced the margin for execution errors, making the company’s ability to scale without excessive leverage or dilution increasingly central to its long-term valuation.