VC Funding Top Ten — September 4, 2026: AI Infrastructure, Cybersecurity, Healthtech

Overview

Friday, September fourth, three PM Pacific. Today's biggest check is a massive three-billion-dollar private equity round for AI infrastructure player Crusoe. It's part of a nearly six-billion-dollar day dominated by the picks and shovels of the AI gold rush. We'll break down the ten biggest deals, from massive data cen

In this show

• Friday, September fourth, three PM Pacific. Today's biggest check is a massive three-billion-dollar private equity round for AI infrastructure player Crusoe. It's part of a nearly six-billion-dollar day dominated by the picks and shovels of the AI gold rush. We'll break down the ten biggest deals, from massive data center plays to a new wave of AI-specific security startups. I'm your host. With me are our Markets and World correspondents. Let's get to the numbers.
• Here's the top-line snapshot. Across ten disclosed rounds, investors deployed $5.98 billion today. The largest, as mentioned, was Crusoe's $3 billion private equity financing. AI was the hottest category, accounting for five of the top ten deals. And in public market news, SoundHound AI completed its acquisition of LivePerson, creating a new conversational AI powerhouse. The story of the day is clear: billions are pouring into AI infrastructure and security, signaling a massive new wave of investment.
• Let's start with that top deal. Crusoe landed a $3 billion private equity round from undisclosed investors. The company builds data centers and cloud infrastructure powered by stranded energy, like flared natural gas. This massive financing highlights two things: the immense capital required to build out AI infrastructure, and the growing demand for more sustainable ways to power it. By using otherwise wasted energy, Crusoe is tackling the massive environmental footprint of large-scale AI.
• The AI infra story continues at number two. Fluidstack raised $1.5 billion in a private equity round led by Jane Street Capital, valuing the company at a staggering $18 billion. Fluidstack provides large-scale GPU and data center capacity specifically for demanding AI workloads. This valuation is a clear signal of just how hot the market is for computing power. Companies that can provide the picks and shovels—in this case, the raw GPU power for training and running advanced AI models—are commanding premium valuations.
• At number three, we move up the stack to the AI operating system. Wonderful raised a $550 million Series C led by Insight Partners, hitting a $5 billion valuation. The company provides a platform for enterprises to automate workflows and coordinate AI agents. Salesforce also participated in the round. This funding is aimed at accelerating global expansion as large companies move beyond isolated AI experiments and toward organization-wide adoption of AI-native applications.
• Back to infrastructure at number four. Gimlet Labs secured a $300 million Series B led by Andreessen Horowitz, pushing its valuation to $3 billion. Gimlet is building an AI inference cloud designed to make running AI models faster and cheaper by distributing workloads across different types of chips. This brings their total funding to $392 million. It’s a highly technical play, but it addresses a critical bottleneck: the cost and complexity of AI inference, which is where models actually generate answers in the real world.
• At number five, a major cybersecurity deal. Upwind Security raised $300 million in a growth round co-led by Bessemer and TCV, valuing the company at $3.8 billion. Upwind focuses on cloud security, combining configuration analysis with live runtime observability to spot and neutralize threats in real-time. For large enterprises, prioritizing which vulnerabilities to fix is a massive challenge. This funding will help Upwind scale its platform that helps security teams focus on the most critical risks.
• Pivoting to robotics at number six. Lyte, a company developing sensing and perception technology for robots, raised a $165 million Series C at a $1.6 billion valuation. The round was led by Maverick Silicon. Founded by former Apple engineers who worked on Face ID, Lyte builds custom silicon and AI software to help robots understand the physical world. With a total of $272 million now raised, the company will scale production for its tech, which is used in manufacturing and warehouse robotics.
• And now for the emerging AI security space. At number seven, HiddenLayer raised a $100 million Series B led by Delta-v Capital. HiddenLayer provides a security platform built specifically to protect AI models and agents from attacks. This is a critical new category, and the market is responding. The company's annual recurring revenue has grown more than tenfold in the past year. This funding will help them expand as more enterprises deploy vulnerable AI systems into production environments.
• Two deals to cover in healthtech and AI security. At number eight, Ultrahuman raised $70 million in a growth round. The health intelligence company makes wearable tech like smart rings, and plans to use the funds to evolve into a human-computer interface company. And at number nine, AIR Security emerged from stealth, raising $50 million in seed funding from Sequoia and Greenoaks. AIR is building a platform to monitor and secure the software components that AI agents use to interact with enterprise systems, a huge emerging risk.
• Rounding out the top ten is Medulance, an emergency healthcare company in India, which raised $2.8 million to expand its ambulance network and invest in 5G-enabled tech. But the big thing to watch today is the rise of AI Security. The significant funding for Upwind, HiddenLayer, and AIR signals a new, rapidly growing sub-sector. As enterprises deploy more AI, securing these complex systems is becoming a top priority. Expect to see a lot more investment and M&A activity in this space.
• That's the deal flow for this Friday. Billions invested in the foundational layers of AI, and a clear signal that securing these new systems is the next major venture opportunity. As we head into the weekend, the pipeline for next week is already building up, with chatter around a major new climate tech fund closing and a potential decacorn valuation for a robotics startup. We'll be here to track it all. That's a wrap for the week. Back Monday afternoon at three PM Pacific with the next deal flow.