Cloud: 10 companies that raised the most in 2025

Overview

The 10 European cloud companies that raised the most in 2025 were led by AI infrastructure firms, with UK-based Nscale on top after combined Series B and C rounds and Netherlands-based Nebius close behind. A small group of very large growth-stage deals accounted for most of the capital, while smaller seed and early-stage rounds spread across cloud optimization, sovereign cloud, and developer platforms. Funding concentrated in the Netherlands, Italy, Germany, Spain, and the UK, with Western Europe leading on both deal count and dollars raised.

Key Takeaways

Nscale, a UK AI cloud and data center company, led the list, with public reporting confirming a record $1.1 billion Series B in September 2025 followed by a $2 billion Series C, the largest of its kind in European history.
Nebius, based in the Netherlands, ranked second on the Tech.eu list and separately raised billions through convertible notes and equity to fund AI infrastructure, backed by a $2 billion strategic investment from NVIDIA.
Cast AI of Lithuania placed third with a $108 million Series C that lifted its valuation to roughly $850 million, the only cloud cost optimization specialist near the top of the table.
Most of the capital flowed to a handful of large growth-stage rounds, while seed, pre-seed, and convertible deals kept early-stage activity alive across the sector.
The companies span several niches: AI compute infrastructure, sovereign cloud, Kubernetes optimization, AI agent environments, and privacy-focused storage.
Funding clustered in the Netherlands, Italy, Germany, Spain, and the UK, with Central and Eastern European firms such as Lithuania's Cast AI and the Czech Republic's E2B also landing notable rounds.

Stats & Key Facts

#Nscale ranked first with roughly $1.53 billion in 2025 funding per Tech.eu, including a confirmed $1.1 billion Series B and a $2 billion Series C
#Nebius placed second at about $1 billion on the Tech.eu list, with separate reporting of a $4.3 billion convertible note offering and a $2 billion NVIDIA investment
#Cast AI raised $108 million in its Series C, reaching an $850 million valuation and serving more than 2,100 organizations
#NexGen Cloud of Spain raised about $45 million for sovereign AI cloud and GPU services
#Impossible Cloud Network raised 28.8 million euros for decentralized cloud infrastructure
#E2B of the Czech Republic raised $21 million to provide secure environments for running AI agents and code

Cloud: 10 companies that raised the most in 2025

Nscale tops European cloud funding with billion-dollar AI infrastructure rounds

The UK company sat at number one by a wide margin.

Nscale led the Tech.eu ranking with roughly $1.53 billion in 2025 funding. The company runs a full-stack AI cloud that ties together GPU compute, AI software tools, and its own and colocated data centers.

Public reporting fills in the detail behind that figure. In September 2025 Nscale closed a $1.1 billion Series B, described as the largest Series B in European history, in a round led by Aker ASA with participation from Dell, Nokia, NVIDIA, Fidelity, and Point72. The company later raised a $2 billion Series C, again billed as a European record.

The money supports a rapid build-out of AI data centers across Europe, North America, and the Middle East, including work tied to large national AI projects.

Nebius rides AI demand to the second spot from the Netherlands

Nebius was the runner-up and a heavy fundraiser in its own right.

Nebius, headquartered in the Netherlands, placed second on the Tech.eu list at about $1 billion. The company supplies GPU clusters and managed infrastructure used to train and run machine learning models.

Outside the list, Nebius raised even larger sums during the year. Reporting points to a roughly $4.3 billion convertible note offering and a separate $3 billion financing, alongside a $2 billion strategic investment from NVIDIA that took an 8.3 percent stake. The company also signed multi-billion-dollar infrastructure deals with Microsoft and Meta.

These figures show how capital-intensive AI cloud has become, with infrastructure providers needing enormous sums to secure chips and build capacity.

Cast AI and the rise of cloud cost optimization

The third-ranked company takes a software-first approach rather than building data centers.

Cast AI, based in Lithuania, ranked third with a $108 million Series C that closed in spring 2025 and pushed its valuation to about $850 million. The round was led by G2 Venture Partners and SoftBank Vision Fund 2.

Instead of selling raw compute, Cast AI uses machine learning to cut cloud costs and tune Kubernetes workloads automatically. The company reports more than 2,100 customers, including Akamai, BMW, and Swisscom.

Its pitch lands at a moment when many companies waste most of what they pay for. Cast AI research found that only about 10 percent of CPU and 23 percent of memory get used across typical cloud environments.

Sovereign cloud and decentralized infrastructure draw mid-size rounds

Several companies in the middle of the list focus on control, location, and ownership of data.

›NexGen Cloud, listed under Spain, raised about $45 million for sovereign AI cloud and on-demand GPU access through its Hyperstack platform.
›Impossible Cloud Network raised 28.8 million euros to build a decentralized network that links independent hardware providers into shared computing capacity.
›PoliCloud of France raised 7.5 million euros to operate modular micro data centers aimed at AI workloads and secure storage.
›These deals reflect European interest in keeping data and compute under local or distributed control rather than relying only on large foreign providers.

Developer platforms and privacy storage round out the top ten

The lower half of the list mixes tools for AI builders with consumer-grade privacy products.

›E2B, from the Czech Republic, raised $21 million to provide secure sandboxes where AI agents and generated code can run safely.
›Akamas of Italy raised $10 million for AI-driven optimization of application performance and infrastructure cost.
›StackGuardian, listed under Belgium, raised $10 million to combine infrastructure-as-code automation with built-in policy controls.
›Internxt of Spain raised 3.3 million euros for end-to-end encrypted, zero-knowledge cloud storage.

What the 2025 numbers say about Europe's cloud market

Reading the list as a whole points to a clear shape for the year.

The gap between the top two names and the rest is stark. Nscale and Nebius together account for the bulk of the capital, a sign that AI infrastructure now absorbs most cloud investment dollars in Europe.

Below them, smaller rounds spread across optimization software, sovereign cloud, developer tooling, and storage. That spread shows a maturing ecosystem with room for both capital-heavy builders and lean software firms.

Geography matters too. The Netherlands, Italy, Germany, Spain, and the UK led activity, while Lithuania and the Czech Republic showed that Central and Eastern Europe now produce fundable cloud companies.

Frequently Asked Questions

Which European cloud company raised the most in 2025?

Nscale, a UK AI cloud and data center company, raised the most on the Tech.eu list at roughly $1.53 billion. That figure reflects a $1.1 billion Series B in September 2025 plus a later $2 billion Series C.

Why did AI infrastructure firms dominate the rankings?

Building and running GPU data centers requires enormous upfront capital for chips, power, and facilities. That need pushed firms like Nscale and Nebius to raise far larger sums than software-focused cloud companies.

What does Cast AI do differently from the top two companies?

Cast AI sells software, not raw compute. It uses machine learning to automatically reduce cloud bills and optimize Kubernetes workloads, and it reached an $850 million valuation with its $108 million Series C.

Which countries were most active in European cloud funding in 2025?

The Netherlands, Italy, Germany, Spain, and the UK led on deal volume and capital. Central and Eastern European countries such as Lithuania and the Czech Republic also produced companies in the top ten.

What is sovereign cloud and why does it appear on the list?

Sovereign cloud keeps data and computing under local or national control rather than relying only on large foreign providers. NexGen Cloud and PoliCloud both raised funding for this approach, reflecting European demand for data control.

European cloud funding in 2025 split into two stories: a few giant AI infrastructure raises that captured most of the money, and a wider set of smaller rounds backing optimization, sovereign cloud, and developer tools. The mix points to a deepening market where both heavy builders and lean software firms find backers.