The 10 biggest startup rounds of 2025 (and why they matter)

Last year was a blockbuster for startups. Investors poured enormous sums into just a handful of companies – dozens of “mega-rounds” of $1 billion or more. In our “The 10 biggest startup rounds of 2025 (and why they matter)” we rank the 10 biggest funding rounds of 2025 globally, each one over $1 billion.

Read on to see who the winners were, how much they raised, who backed them, and why those rounds made headlines.

1. OpenAI – $40 billion (USA, AI)

No surprise – the top spot goes to OpenAI, maker of ChatGPT. In Q1 2025 it closed a staggering $40 billion funding round. That round was reportedly led by SoftBank and catapulted OpenAI’s post-money valuation to about $300 billion. This all-in bet on AI means OpenAI will have enormous resources to build new products (like advanced chatbots and AI tools), but it also raises the stakes for AI safety and regulation. Investors clearly believe OpenAI will keep dominating AI, and this mega-round makes it one of the most valuable private startups in history.

2. Anthropic – $13 billion (USA, AI)

The runner-up is Anthropic, an AI startup co-founded by former OpenAI leaders. In September 2025 it closed a $13 billion Series F led by ICONIQ Capital (with Fidelity, Lightspeed and others co-leading). That deal valued Anthropic at about $183 billion. Anthropic makes “Claude,” a direct competitor to ChatGPT. This huge funding haul (the third-largest ever raised by a U.S. startup) shows that investors are betting big on multiple AI champs, not just OpenAI. The money will be used to scale up Claude’s technology – Anthropic’s run-rate revenue was already reportedly hitting $5 billion per year by late 2025. In short, Anthropic’s $13 billion round signals confidence that the AI boom has room for more winner.

3. Project Prometheus – $6.2 billion (USA, AI + Robotics)

Jeff Bezos quietly launched a new AI company called Project Prometheus and raised $6.2 billion in seed funding. Bezos himself and other investors provided the cash (details are scarce), making it the third-biggest deal of 2025. Prometheus is focused on applying AI to physical engineering tasks. In other words, it aims to use machine learning to improve manufacturing, robotics and aerospace – even technologies Bezos might use at his space venture, Blue Origin. This shows that even the richest tech veterans are making giant AI bets. For founders and VCs, a Bezos-backed $6.2 billion round is a signal that the AI gold rush isn’t over yet.

4. xAI – $5.3 billion (USA, AI)

Elon Musk’s AI startup xAI raised about $5.3 billion (Series B) in mid-2025. The exact investors are kept under wraps, but reports suggest backers include tech billionaires (like Meta’s Peter Thiel) and venture funds tied to Nvidia and others. xAI is working on its own large language models and even custom AI chips. This massive round – the fourth-largest of the year – means xAI can build a big team and compute cluster to challenge ChatGPT and others. The deal shows that even Musk’s ventures can rally large funding when AI hype is this hot. Investors clearly see potential in another well-funded AI lab, even if xAI’s products are still in early stages.

5. Infinite Reality – $3 billion (USA, VR/AR)

Not all mega-rounds were AI-only. Infinite Reality (USA) pulled in about $3 billion in early 2025. This startup, backed by top gaming and entertainment investors, is building advanced virtual/mixed reality worlds (for the so-called metaverse). Think ultra-realistic VR where people can work, socialize or play. Raising $3 billion put Infinite Reality at #5 on our list. It shows investors believe in immersive tech: if the metaverse or VR/AR suddenly takes off, Infinite Reality wants to be ready. This round will fund faster hardware and more content creation. In plain language: it’s a huge bet that digital reality is worth billions in the near future.

6. Anysphere – $2.3 billion (USA, AI)

Anysphere (USA) scored a $2.3 billion round in November 2025. This one closed in under two years since Anysphere’s founding – lightning speed. Anysphere makes “Cursor,” an AI coding assistant that helps programmers write software (imagine ChatGPT tuned for code). The round was led by top VCs (Accel and Coatue) and pushes Anysphere into the unicorn stratosphere. With $2.3 billion, Anysphere can hire aggressively and improve its code-AI model. It’s a sign that investors see big value in AI tools for developers – essentially betting that writing software with AI will be a huge market. In short: this massive raise means Anysphere will be a name to watch in AI-for-coding.

7. Mistral AI – $2 billion (France, AI)

Europe’s largest deal was Mistral AI (France), which raised about $2 billion in Q3 2025. Mistral, co-founded by former Meta AI researchers, makes large language models and has been dubbed “the French AI champion.” Their round was co-led by Atomico and Lightspeed and included big European and US investors. A $2 billion cash influx – one of the top 10 deals – shows that the AI gold rush isn’t just Silicon Valley’s domain. Investors poured funds into Mistral to keep Europe competitive in AI. The money will fuel more model research and scaling up data centers in Europe. It’s a bold bet that a European startup can capture a slice of the global AI market.

8. Binance – $2 billion (Global, Crypto)

Binance, the world’s largest cryptocurrency exchange (registered in the Cayman Islands), also landed a $2 billion funding round in Q1 2025. This was a private token sale led by big financial investors (Temasek and others). Binance isn’t building AI – it’s a crypto exchange – but it attracted a mega-round anyway. The funds are earmarked for expanding Binance’s services (like NFT marketplaces and Web3 ventures) and bolstering its war chest amid crypto volatility. That Binance could raise $2 billion shows investors are still betting on cryptocurrency infrastructure, even after shaky markets. In context, this was the only non-AI entry in the top 10, underscoring crypto’s continuing influence in tech funding.

9. Lambda – $1.5 billion (USA, AI Hardware)

Lambda (USA) raised about $1.5 billion in November 2025. Lambda makes purpose-built servers and chips optimized for AI and machine learning. As companies race to build bigger AI models, Lambda’s machines are in demand. This round (led by an AI-focused fund TWG Global) will allow Lambda to ramp up manufacturing and global distribution. It highlights that some of the richest bets are on the “plumbing” of AI - not just the software. By funding Lambda, investors are saying: building and training next-gen AI models requires special hardware, and Lambda is well-positioned to supply it.

10. Princeton Digital Group – $1.3 billion (Asia, Data Centers)

Rounding out #10 is Princeton Digital Group (PDG), an APAC data-center operator. In mid-2025 it raised $1.3 billionfrom Stonepeak. PDG builds and runs huge data centers across Asia (India, Singapore, Japan, etc.) – the backbone for cloud and AI services. This deal may not sound “techy,” but it reflects real demand. Cloud providers and AI companies need massive infrastructure in Asia, and PDG is a key player there. With $1.3 billion in fresh capital, PDG can expand more campuses to meet the AI/data boom. Including PDG shows that mega-rounds also went to core tech infrastructure (not just apps). It’s the only data-center/company on the list, and it signals: AI and internet growth in Asia require massive data centers, and investors poured big money into building them.

Each of these mega-rounds was global (companies from the US, Europe or Asia) and across sectors (AI software, chip hardware, crypto, VR, data centers). Together they tell the story of 2025: a handful of companies grabbed a huge share of all venture funding. With the top four rounds all AI deals, it’s clear the AI boom drove the funding surge. The others show areas where growth is expected (crypto, metaverse, cloud infrastructure). These 10 deals each made headlines and shifted the startup landscape by pumping billions into tomorrow’s tech.

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