Nebius Group said Wednesday it plans to raise $4.5 billion through a private placement of convertible senior notes, money it will use to build data centers and expand its AI cloud platform. Investors responded by selling the stock, which fell more than 6% on the day.
The move caps a busy stretch for the Amsterdam-based company. A day earlier, Nebius said it would switch its data centers to fuel cells made by Bloom Energy, a technology bet on cheaper, faster-to-deploy power for AI computing. Wednesday’s note sale is the financing side of the same strategy: Nebius is spending at a pace that requires constant access to new capital.
Convertible notes are a familiar tool for companies that need money without selling stock at what they consider the wrong price. The notes carry interest and can later be converted into shares, which means dilution comes later, if at all. For Nebius, the structure has a particular appeal: the company’s stock has been one of the more volatile in the AI infrastructure complex, and its managers would rather not sell equity into that tape. The terms of the notes, including the coupon and the conversion premium, have not been disclosed, and the pricing will tell investors how the market views the company’s risk.
The need for the money is not in dispute. Building AI data centers is one of the most capital-intensive businesses in the world, and the pace of construction has turned borrowing into a competitive sport. Nebius’s larger rivals have raised billions in debt and equity in recent years, and the company has said it intends to match their ambitions, if not their size. The $4.5 billion notes are a down payment on that claim.
The comparison the market keeps making is with CoreWeave, the Nvidia-backed cloud provider that became the public symbol of AI infrastructure’s appetite for capital. CoreWeave built its business on debt, on long contracts and on the willingness of lenders to finance machines that power AI models. Nebius is trying to follow the same playbook, albeit with a different history and a different shareholder base.
That history is worth recalling. Nebius emerged from the breakup of Yandex, the Russian internet giant, and relisted on Nasdaq in late 2024 with Nvidia as an investor. The company kept Yandex’s cloud and AI engineering talent while shedding its Russian operations, and it has since pitched itself as a neutral, Western-owned provider of AI infrastructure. The convertible sale is the strongest signal yet that the company intends to compete for the largest contracts in the industry.
Investors’ hesitation is easy to understand. Convertible notes dilute existing shareholders when they convert, and a $4.5 billion issue is large relative to Nebius’s market value. The 6% drop on the announcement day reflects that arithmetic. But the market’s real question, analysts said, is whether the money arrives in time. The AI infrastructure buildout has a winner-take-most quality: the providers with the most capacity and the fastest delivery win the biggest customers, and the ones that hesitate get left with the leftovers.
The Bloom Energy decision adds another layer. Fuel cells can be installed faster than grid connections and traditional gas plants, and for AI providers, speed to power is often the binding constraint on growth. Nebius is treating energy as part of its product, not just a cost, and the fuel-cell pivot is an attempt to out-hustle rivals on the one input nobody can fake.
The convertible market itself has become a fixture of the AI boom. OpenAI raised a record convertible round last year, and a string of AI infrastructure companies have followed, using notes to fund everything from chips to electricity. The instruments suit the moment: they give fast-growing companies cash now and let the equity markets decide the price later. Nvidia, which holds a stake in Nebius, has also been routing its partner-cloud customers toward the providers that can add capacity fastest, a relationship that gives Nebius a pipeline of demand if it can build fast enough to serve it.
For Nebius, the test is execution. The company has the customers, the engineering team and now the capital, but it is competing against companies with deeper pockets and longer track records. Whether $4.5 billion is enough to close the gap with CoreWeave and its peers is a question the market will answer quarter by quarter. For now, Nebius has done what the race demands: raised the money and gotten back to building. The next filing, and the next data-center announcement, will show whether the capital is turning into capacity fast enough to matter. In this business, the check that clears is only the beginning.
