BigBear.ai vs. Nebius: Which Tech Stock Is a Better Buy in 2026?

AI continues to transform the corporate landscape, but choosing the right stock remains challenging given the sheer number of options. Should you bet on BigBear.ai (NYSE:BBAI) or the infrastructure-focused Nebius Group (NASDAQ:NBIS)?

These companies target the AI market from opposite sides. BigBear.ai provides software solutions primarily for defense and government intelligence, while Nebius Group builds the cloud infrastructure required to train advanced models. While they both operate in the technology sector, their financial profiles suggest very different paths for investors.

The case for BigBear.ai

BigBear.ai specializes in decision-intelligence and autonomous software for the defense and intelligence sectors. The company typically uses a prototype-first model to secure long-term government sales, deploying minimally viable products before moving to full-scale arrangements.

Customer concentration like this adds a layer of risk to the business, as roughly 51% of 2025 revenue came from customers contributing more than 10% of total sales. These contracts often allow for termination for convenience, which can create volatility in future revenue streams.

In 2025, revenue reached nearly $128 million, a 19% decline from the prior year. The company reported a net loss of approximately $294 million for the same period. This performance continued a trend of net losses seen in previous fiscal years, despite the high demand for analytics among tech stocks.

As of its December 2025 balance sheet, the debt-to-equity ratio was nearly 0.2x, indicating that total debt is negligible relative to shareholders' equity. The current ratio, which measures the ability to cover short-term debts with current assets, was roughly 1.8x.

As of Q2 2026, trailing-12-month free cash flow was negative $73 million, representing cash flow from operations minus capital expenditures. Because the company is not yet generating positive cash from its operations, it must rely on existing liquidity to fund its growth initiatives.

The case for Nebius

Nebius operates as an AI cloud infrastructure provider, building the full-stack environments required for model training and deployment. The company maintains a global footprint with data center hubs across Europe and the United States to serve AI builders.

Its platform targets enterprises in healthcare, robotics, and financial services. By offering end-to-end infrastructure, it aims to capture the high capital investment currently flowing into the AI sector.

In 2025, revenue reached nearly $530 million, marking a significant increase of approximately 479% over the previous year. The company reported net income of approximately $82 million, achieving a positive net margin of roughly 15%. This growth trajectory highlights the rapid expansion of its cloud services as enterprises rush to secure computing power for AI workloads. This leap in revenue demonstrates the intense demand for training capacity in the global market.

As of its December 2025 balance sheet, the current ratio was approximately 3.1x, suggesting a strong ability to meet short-term obligations. The debt-to-equity ratio was nearly 1.1x, comparing the company's total debt to its shareholders' equity.

As of Q2 2026, TTM free cash flow was approximately negative $5.9 billion, reflecting the large capital expenditures needed to purchase GPUs and other hardware to expand its data center infrastructure.

Risk profile comparison

BigBear.ai faces significant risks, including dependency on the U.S. public sector, which makes it vulnerable to budget deficits and procurement delays. Furthermore, it faces intense competition from massive system integrators and leading tech companies.

Nebius Group operates in an extremely capital-intensive industry and must compete with the world's largest cloud providers. Its massive negative free cash flow indicates the high cost of building and maintaining global data centers. Because it faces competition from other hyperscalers, the company must maintain a rapid pace of innovation. Investors should also consider the execution risks involved in scaling infrastructure across multiple international jurisdictions.

Valuation comparison

Nebius commands a much higher sales multiple than BigBear.ai, reflecting its explosive revenue growth despite significant capital spending requirements.

The P/S ratio measures a company's market value against its sales over the past twelve months. The Forward P/E compares the stock price to future earnings estimates.

Valuation metrics include those sourced from Financial Modeling Prep (FMP) and may differ from those of other data providers.

Which stock would I buy in 2026?

I would buy Nebius. Despite its negative free cash flow, it is growing revenues and reporting a profit on a GAAP basis. BigBear.ai has reported inconsistent financial results and continues to report large losses on the bottom line. This reflects a more difficult path to growth for BigBear in winning government contracts.

Importantly, Nebius is pursuing a much bigger market than BigBear.ai. The addressable market for GPU cloud infrastructure is estimated to be $1 trillion. Nebius is not going to capture all of it. Still, if it can capture just 10% of that opportunity, it could generate $100 billion in revenue and deliver significant returns for investors.

BigBear.ai aims to make strategic acquisitions to expand, but Nebius doesn't have to do so. It is seeing higher prices per megawatt of data center capacity, indicating a solid competitive position and pricing power.

Overall, I would buy the stock that is posting consistently high revenue growth and building infrastructure for the AI-driven economy. Nebius has a much higher ceiling to generate wealth-building returns over the long term.

John Ballard has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.