The cash is in. Silicon Valley venture firm Series X Capital has closed its third flagship fund at $150 million. The vehicle, dubbed Fund III, will back early-stage founders building AI infrastructure and edge computing technologies.
It is a massive win in a brutal fundraising market. Many general partners are currently struggling to raise capital as institutional investors tighten their purse strings. Yet Series X found a sweet spot. They are focusing on the physical and software backbone of the AI boom rather than the consumer-facing applications that have recently saturated the market.
Funding the Plumbing of Artificial Intelligence
“Everyone is excited about chatbots and generative art, but those tools do not run on thin air,” said Marcus Vance, co-founder and managing partner at Series X. “They require staggering amounts of computational power, smarter data pipelines, and highly optimized hardware. That is where we are investing. We want to fund the plumbing.”
Fund III plans to write checks ranging from $2 million to $5 million for seed and Series A rounds. The team expects to build a portfolio of roughly 25 startups over the next three years. This represents a step up from their second fund, which closed at $90 million in 2021 and focused more broadly on enterprise software.
Why the Edge Is the Next Frontier
This time around, the spotlight is firmly on edge computing. As AI models grow larger, sending every single data query back to centralized cloud servers is becoming unsustainable. It is too slow, too expensive, and eats up too much bandwidth. Edge computing solves this by processing data directly on local devices—like factory sensors, connected cars, or medical equipment.
Sarah Jenkins, a general partner who joined Series X last year to lead their deep-tech investments, believes the shift to the edge is inevitable.
“If an autonomous delivery drone needs to make a split-second decision, it cannot wait for a round-trip data transfer to a server farm three states away,” Jenkins explained. “The decision-making has to happen right there on the device. The startups creating the ultra-low-power chips and localized models to make this possible are the ones we are looking for.”
Track Record and Investor Confidence
The firm’s LPs, which include university endowments, pension funds, and family offices, seem to agree. According to Vance, the fundraising process took just under nine months. That is incredibly fast by today’s standards, where many funds drag on for eighteen months or more.
Part of the quick close stems from the track record of Series X’s earlier vehicles:
- Fund I (2018): Recently posted a net internal rate of return (IRR) of 34%, driven by early bets on data orchestration tools and specialized cloud databases.
- Fund II (2021): Has shown strong paper gains, though several of its portfolio companies are still in the mid-stages of growth.
However, investing in hardware and deep infrastructure carries unique risks. These startups usually require more capital and longer development cycles than traditional software companies. They cannot just launch a beta version in a weekend.
Vance is not deterred by the capital intensity of infrastructure startups. “Yes, hardware is hard,” he admitted. “But it also creates incredibly deep competitive moats. Once an enterprise integrates a specific hardware architecture or a core data pipeline tool into their operations, they do not just rip it out the next year. The stickiness of these businesses is unmatched.”
Deploying the Capital
Series X is already putting the new capital to work. The firm has quietly closed its first two investments from Fund III:
- An Austin-based startup designing energy-efficient neuromorphic chips for industrial IoT devices.
- A Boston-based team building a decentralized platform to train smaller, specialized AI models across distributed networks.
With $150 million ready to deploy, Series X is positioning itself at the front of the next wave of tech infrastructure. The software layer of AI has had its moment in the spotlight. Now, the focus is shifting to the physical and structural foundations that will keep the entire ecosystem running.
