Nebius vs CoreWeave vs Iris Energy: Who Wins the Neocloud War?

The AI infrastructure market is in the middle of a brutal reality check. The question is no longer "build it and they will come" — it's one far more terrifying question: who is actually going to pay for all these GPUs?

Three publicly traded companies are fighting to become the "AWS of the AI era": Nebius Group ($NBIS), CoreWeave ($CRWV), and Iris Energy ($IREN). When you strip away the marketing narratives and look at how each one is actually financing its expansion, a clear winner emerges.

This is our full comparative analysis, covering valuation metrics, GPU fleets, capital structures, bull and bear cases for each company, and a verdict. We've followed all three closely — including holding a personal position in $NBIS — so this isn't written from the outside looking in.

Head-to-Head Comparison Table

All figures are estimates based on Q4 2025 / early 2026 data. Valuation metrics reflect conditions at time of writing and will change.

Sources: Company earnings releases, public filings, analyst estimates. Figures are approximations and subject to change. Not investment advice.

1. What Is the Neocloud Sector?

The term "neocloud" describes a new generation of cloud infrastructure companies built specifically for AI workloads. Unlike traditional cloud providers (AWS, Azure, Google Cloud), which offer general compute, neoclouds specialise in GPU-dense clusters for training and running large AI models.

The economics are simple in theory and brutal in practice. AI companies need thousands of expensive NVIDIA GPUs running simultaneously to train models like GPT, Claude, and Llama. They can rent capacity from hyperscalers, but hyperscaler pricing is high and availability is constrained. Neoclouds step in as alternatives — often with faster provisioning, more specialised infrastructure, and competitive pricing.

The catch is the upfront capital required. You need to buy the GPUs (currently $25,000–$40,000 each for H100s), build or lease the data centre space, secure the power, and run the cooling — all before earning a single dollar of revenue. This is why how each company finances this buildout is the defining variable in the neocloud investment thesis, not just the GPU count.

If you're new to individual stock investing and want a solid grounding first, read our guide on how to research individual stocks or our piece on index funds vs ETFs to understand why most investors should start with diversified funds rather than speculative single stocks.

2. CoreWeave ($CRWV): Revenue Beast, Debt Monster

CoreWeave entered the neocloud race earlier than most and secured a remarkable commercial position. They have Nvidia's backing, a strong client roster including OpenAI and Microsoft, and posted $1.57 billion in Q4 2025 revenue — a 110% YoY increase. By any revenue metric, CoreWeave is the largest pure-play neocloud company in the world right now.

The Financing Problem

CoreWeave funded this growth almost entirely through debt. Market estimates put their total debt load at $29 billion to $29.8 billion as of early 2026. To put that in context: their market cap at IPO was roughly equivalent to their total debt pile. That is an extraordinarily levered capital structure for a company with significant ongoing CapEx requirements.

The neocloud model requires constant reinvestment. As GPU generations advance (H100 → H200 → Blackwell), companies must refresh their fleet or risk pricing out of the market. CoreWeave is servicing $29B+ in debt while simultaneously having to fund the next round of GPU purchases. The interest on that debt alone likely exceeds hundreds of millions of dollars annually.

CoreWeave Infrastructure Details

CoreWeave operates across multiple US data centre regions, with significant deployed capacity in New Jersey, Virginia, and Texas. Their fleet is primarily NVIDIA H100 and H200 GPUs, with access to early Blackwell (B200) systems. They also provide Kubernetes-based GPU orchestration through their CoreWeave Cloud platform.

One underappreciated risk: CoreWeave's largest client is OpenAI, which Microsoft has been steadily pulling into its own Azure infrastructure. If that migration accelerates, CoreWeave's backlog figures need recalibrating.

3. Iris Energy ($IREN): Great Economics, Wrong Timing

Iris Energy occupies a unique position in the neocloud landscape. Unlike CoreWeave or Nebius, IREN owns its infrastructure outright — and powers it with some of the cheapest electricity available. Their Childress, Texas facility runs on approximately 3 cents per kilowatt-hour, enabling extraordinary unit economics once the GPUs are in place.

The absence of software overhead also means simpler, more capital-efficient operations. No proprietary platform to maintain. No software engineering headcount. Just bare metal GPU compute at scale. This drives IREN's estimated EBITDA margins of approximately 85% — among the highest in the sector.

The Dilution Problem

The challenge is getting there. IREN has the capacity — 4.5GW of theoretical power — but not the capital to fill it with GPU clusters. Their solution has been At-The-Market (ATM) share offerings: selling new shares into the market to raise cash for GPU purchases.

Their most recent filing: a $6 billion ATM facility at an $11.7 billion market cap. That's roughly a 51% potential dilution of existing shareholders. What makes this particularly painful for current buyers is that the stock has traded below the price at which the ATM launched — meaning they have to issue even more shares to raise the same amount of capital, compounding the dilution.

IREN Infrastructure Details

Iris Energy's flagship Childress, TX site benefits from access to cheap renewable power from West Texas wind. They have pursued co-location and power purchase agreements that allow them to lock in low long-term energy costs — a structural advantage that CoreWeave and Nebius, both leasing data centre space, cannot easily replicate. The long-term question is whether low-cost owned infrastructure beats high-cost leased infrastructure with software orchestration.

4. Nebius Group ($NBIS): The Smartest Capital Structure

Nebius was spun out of Russia's Yandex following Western sanctions in 2022 and has since repositioned as a European-headquartered, global AI infrastructure company. Their flagship product is an AI cloud platform that offers GPU compute, storage, networking, and proprietary software orchestration for AI workloads — comparable to what AWS offers for general compute, but built specifically for AI.

Q4 2025 revenue hit $228 million — up 547% year-over-year — with positive operating cash flow. For a company that barely existed in its current form two years ago, those numbers are extraordinary.

The Capital Structure Advantage

Where Nebius genuinely differentiates itself is in how it finances growth. Rather than high-interest debt (CoreWeave) or retail dilution (IREN), Nebius has structured its $4.34 billion debt pile primarily as 0% convertible notes. The largest facility — $2 billion — comes directly from Nvidia as part of a strategic partnership. Nvidia wants Nebius to succeed because Nebius buys their GPUs; the 0% financing is Nvidia skin in the game.

Convertible notes do create short-term share price pressure. Holders short the stock to hedge their conversion rights, which suppresses near-term appreciation. But the interest cost is essentially zero — a stark contrast to the hundreds of millions CoreWeave likely pays annually on $29B+ of conventional debt.

Additionally, management has guided that 60% of future growth spending will be funded by customer prepayments — primarily from Meta and Microsoft. These two hyperscalers are essentially pre-purchasing capacity, de-risking the buildout for Nebius shareholders.

Nebius Infrastructure Details

Nebius operates GPU data centres across Europe and North America, including a significant deployment at the Vineland, NJ site. Their infrastructure is built around NVIDIA H100 and H200 clusters, with H100 availability being a competitive differentiator when hyperscalers faced GPU shortages in 2023–2024. Their platform includes managed Kubernetes for AI, storage optimised for large model checkpointing, and integrated networking at the 400GbE level required for large-scale distributed training.

5. Sector-Wide Risk Factors

Beyond the company-specific risks above, all three companies face structural headwinds that any investor should understand before committing capital.

6. Valuation Framework: How to Think About These Stocks

All three companies are pre-profitable on a net income basis, which means traditional P/E analysis is not applicable. Investors are instead using revenue multiples, EV/EBITDA projections, and backlog-to-market-cap ratios as primary valuation frameworks.

For Nebius specifically, the $46B+ backlog against a ~$10–12B market cap implies an EV/Backlog ratio below 0.3x — which is striking for a company growing revenue at 547% YoY. The bear argument is that backlog doesn't equal revenue (execution risk, timing, etc.), but even discounting heavily, the backlog-to-cap ratio is compelling.

For CoreWeave, the challenge is that any revenue multiple analysis must account for the $29B+ debt pile. Enterprise value (equity + net debt) is significantly higher than market cap, which distorts headline revenue multiples. On an EV/Revenue basis, CoreWeave may actually be more expensive than it appears on a market-cap/revenue basis.

For IREN, the pure infrastructure play is best valued on a $/MW-deployed or $/GPU basis, adjusted for the dilution discount. The key question is what EBITDA multiple a fully-loaded IREN infrastructure business deserves — which depends heavily on how many GPUs actually get deployed and at what utilisation rates.

For broader context on how to evaluate growth stocks vs defensive holdings in a portfolio, our piece on S&P 500 vs FTSE 100 index funds explains why most investors should have the bulk of their portfolio in diversified index funds rather than individual high-risk stocks like these.

7. The Verdict: A 5-Year Horizon Ranking

The current macro environment — falling indices, geopolitical uncertainty, rate cuts delayed — does not favour short-term holders in any of these names. All three will experience continued volatility. With that framing, here is our 5-year ranking:

8. Community Sentiment: What the Retail Investor Consensus Shows

The Reddit investment community provides a useful real-time sentiment signal for all three names, and the split is revealing.

r/NBIS_Stock (19,000 members) is dominated by long-term conviction holders buying into weakness. The prevailing tone is not momentum chasing but thesis-based accumulation — investors who understand the backlog, the convertible note mechanics, and the Q4 2026 inflection point. The community's most-upvoted posts are about the infrastructure thesis, not short-term price targets.

CoreWeave sentiment on broader investing forums has been notably cautious post-IPO. The institutional repricing happened quickly as analysts processed the debt figures. Retail sentiment is split between those who see the revenue growth as justifying the risk and those who worry that CoreWeave becomes a debt-servicing story rather than a growth story.

IREN bulls on Reddit frequently cite the $1B ATM raise at $2B market cap that eventually worked out well for patient holders. The bear counter-argument — that the 50% ATM facility at a declining stock price creates a far worse dilution dynamic than past raises — doesn't get enough airtime in bullish IREN communities.

Frequently Asked Questions

How This Fits Into Your Portfolio

High-conviction speculative positions like NBIS, CRWV, or IREN should represent a small fraction of a well-diversified portfolio — not the core. The core should be boring and reliable. Here's how to think about building that foundation:

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• How to Invest £100 a Month in the UK — building the habit before taking on individual stock risk
• What Is Nebius? Our Original NBIS Deep Dive — the backstory on how we first analysed this company
• S&P 500 vs FTSE 100: Which Index Fund? — the diversified baseline that should anchor any long-term portfolio