In short: SiFive, the RISC-V chip IP firm founded by the Berkeley engineers who created the open-source instruction set architecture, raised $400 million in an oversubscribed Series G on April 9, 2026, at a valuation of $3.65 billion. The round was led by Atreides Management and backed by Nvidia, Apollo Global Management, D1 Capital Partners, Point72 Turion, T. Rowe Price Investment Management, Capital Group, Prosperity7 Ventures, and Sutter Hill Ventures. CEO Patrick Little described it as the company’s final private funding round before an initial public offering.

Open source, closed competition

RISC-V (pronounced “risk five”) is an open-source instruction set architecture, the foundational specification governing how a processor interprets and executes instructions, developed at the University of California, Berkeley, from 2010 onwards. Unlike the proprietary architectures maintained by Arm Holdings and Intel, RISC-V is free to implement, extend, and commercialise without per-unit royalties or usage restrictions. SiFive was founded in 2015 by three of the project’s principal architects: Krste Asanović, Andrew Waterman, and Yunsup Lee, working alongside David Patterson, a Turing Award winner and co-author of the standard text on computer architecture. The company’s business model is structurally similar to Arm’s: it designs CPU intellectual property and licences that IP to customers who integrate it into their own silicon, rather than fabricating chips itself. The critical difference is that SiFive’s designs sit on an architecture that no single company controls.

That independence became more commercially valuable in March 2026, when Arm launched its AGI CPU, its first in-house silicon product in its 35-year history, with Meta and OpenAI as debut customers. The move repositioned Arm from a neutral IP licensor into a company with direct hardware ambitions, creating the kind of vertical conflict that has historically pushed technology buyers toward open-standard alternatives, and generating fresh urgency for a competitor that owes no allegiance to any proprietary architecture owner. Intel attempted a different route into the space: in 2021 the chipmaker offered more than $2 billion to acquire SiFive outright, a deal that collapsed over valuation disagreements. Intel has since joined Elon Musk’s Terafab as a foundry partner in April 2026, committing its 18A process node to a $25 billion AI compute facility backed by Tesla, SpaceX, and xAI, a strategic reorientation that leaves the RISC-V IP licensing position without Intel as a would-be acquirer or rival.

The Series G: who invested, and why

The $400 million Series G was led by Atreides Management, a Boston-based investment firm managed by Gavin Baker, who built his reputation running Fidelity’s OTC Portfolio before founding Atreides in 2019. New participants include Nvidia, Apollo Global Management, D1 Capital Partners, Point72 Turion, and T. Rowe Price Investment Management. Existing shareholders Prosperity7 Ventures, Capital Group, and Sutter Hill Ventures also participated. The round closed oversubscribed and lifts SiFive’s total valuation to $3.65 billion, up from the $2.5 billion set at the Series F in March 2022. Nvidia’s presence on the cap table is a technical statement as well as a financial one: in January 2026 SiFive announced it is integrating NVLink Fusion into its high-performance data centre platform, enabling RISC-V-based CPUs to connect directly to Nvidia GPUs via a coherent, high-bandwidth interconnect that reduces latency and improves system utilisation for large-scale AI inference. That compatibility positions SiFive’s CPU IP to work alongside the Vera Rubin platform Nvidia announced at GTC 2026, the company’s next-generation GPU architecture targeting agentic AI workloads.

The broader investment context is one of accelerating hyperscale demand for custom silicon. Amazon committed $50 billion to its Trainium chip programme in its April 2026 shareholder letter, positioning in-house AI silicon as a strategic infrastructure necessity rather than an optional enhancement. The deal between Google, Anthropic, and Broadcom for custom AI compute represents a parallel approach, using purpose-built ASICs to reduce dependence on commodity processors across hyperscale inference workloads. SiFive’s pitch is that it offers hyperscale customers a third path: RISC-V CPU IP that is fully customisable, architecturally independent, and built on an open standard that no single acquirer can lock down. “Hyperscale customers have made it very clear that it is time to accelerate the availability of open standard alternatives for the data centre,” said CEO Patrick Little. “Their consistent ask is for customisable CPU solutions in IP form, that will enable them to meaningfully differentiate their data centre compute solutions.”

What the capital will build

SiFive has outlined three areas of deployment for the Series G capital. Advanced research and development takes the largest share, focused on expanding the roadmap of high-performance scalar, vector, and matrix RISC-V CPU IP, accelerator cores, and system IP targeting data centre deployments. A second allocation covers software ecosystem development, including existing efforts to port CUDA, Red Hat Enterprise Linux, and Ubuntu to RISC-V, work that is critical to making the architecture practically deployable in production data centres where software compatibility is as important as raw performance. The third allocation supports customer enablement: the direct engineering collaboration that helps hyperscale clients and system vendors integrate SiFive IP into their own silicon programmes. Little framed the company’s open-standard positioning as a structural advantage that compounds over time: “RISC-V was created by our founders to be similar to other open standards, driven and continually improved by collaboration and cross-pollination across a broad community of innovators. This ensures choice and flexibility for customers, and ultimately benefits consumers.” He argued that the market is becoming more receptive to open-standard alternatives precisely as Arm moves further into selling its own branded hardware.

Ten billion cores and the IPO signal

SiFive reported record growth in 2025, with its IP featured in more than 500 semiconductor designs and more than 10 billion RISC-V cores shipped to date across consumer electronics, automotive systems, and data centre processors. The company has framed the data centre segment as a potential $100 billion-plus addressable market, driven by the agentic AI infrastructure buildout that has prompted every major hyperscaler to commit tens of billions of dollars annually to compute expansion. Patrick Little told Reuters that the April 2026 fundraise is the company’s final private round before an IPO, though no exchange or pricing timeline has been confirmed. The signal carries weight: a valuation of $3.65 billion and a roster of investors that includes a major GPU manufacturer, a bulge-bracket alternative asset manager, and two prominent long-only asset managers suggests SiFive is preparing for the kind of institutional scrutiny that accompanies a public filing. As AI chip investment reached record levels in 2025, with capital flowing to custom silicon programmes at every major cloud provider, SiFive’s timing places it squarely at the centre of a market transition it has been building toward for a decade.