Onyx Bio Raises $8M Seed Led by Dimension Capital for Virtual Immune System

Onyx Bio Closes $8M Seed Round

Onyx Bio, a Berkeley, California-based research collective, has raised an $8,000,000 Seed round in USD, dated October 8, 2026. The round was led by Dimension Capital.

Participating investors include:

• Dimension Capital (lead)
• Robot Ventures
• Refactor Capital
• Haystack Ventures
• Standard VC

What Onyx Bio Builds

Onyx Bio is building a virtual immune system — a longitudinal model of how real people respond to infection, inflammation, and treatment.

The company's approach is built on a research collective model. Members join paid, at-home studies in areas such as autoimmune disease and immune aging. While enrolled, Onyx Bio measures roughly 1,000 proteins, single-cell gene expression, metabolites, and genetic variation, alongside clinical histories, in order to trace how each individual immune system changes over time.

Critically, every sample is processed in Onyx Bio's own Berkeley lab. That vertical integration gives the company control over sample handling and data quality, and it means the resulting dataset is generated end-to-end under one roof rather than assembled from third-party lab partners.

The stated purpose of the dataset is to give biologists and AI researchers ground-truth data to develop precision medicines faster and more safely.

Traction at Launch

Nearly one thousand members had joined by the company's October 2026 launch. That figure is notable for a seed-stage company operating a longitudinal study model, where member enrollment is the gating factor for everything downstream — sample volume, dataset depth, and the statistical power of any model trained on the resulting data.

Round Summary

• Company: Onyx Bio
• Round type: Seed
• Amount: $8,000,000 USD
• Date: October 8, 2026
• Lead investor: Dimension Capital
• Participating investors: Robot Ventures, Refactor Capital, Haystack Ventures, Standard VC
• Stage: Seed
• Headquarters: Berkeley, California
• Model: Paid, at-home longitudinal studies with in-house lab processing

Why It Matters

The pitch behind Onyx Bio rests on a familiar problem in immunology: the immune system is dynamic, but most of the data used to study it is cross-sectional — a snapshot from a single point in time, often from a patient already in a clinical setting. Longitudinal data from real people, collected repeatedly over time and paired with clinical history, is considerably harder to assemble.

Onyx Bio's answer is to recruit members directly and pay them to participate from home, then run the assays itself. The breadth of the measurement panel — proteins, single-cell gene expression, metabolites, and genetic variation — is what makes the dataset potentially valuable for AI-driven modeling. A model of immune response needs many dimensions of input to be useful, and the company is collecting several of them simultaneously.

The focus areas, autoimmune disease and immune aging, are both areas where the trajectory of the disease matters as much as any single measurement. Immune aging in particular is a field where longitudinal cohorts are scarce and where the ability to observe change over time is the core scientific asset.

The Investor Signal

Dimension Capital leading the round, alongside a syndicate that includes Robot Ventures, Refactor Capital, Haystack Ventures, and Standard VC, gives Onyx Bio a mix of backers. The $8 million seed is a substantial check for the stage and reflects the capital intensity of running an in-house lab alongside a member-facing study operation.

What to Watch

For observers tracking Onyx Bio — as a data partner, collaborator, or acquisition target — the metrics that matter are the ones the funding announcement does not cover: retention of the nearly one-thousand-member cohort over time, the cadence of repeat sampling, and whether the resulting dataset proves useful enough to attract the biologists and AI researchers the company is explicitly courting.

The Berkeley lab is the operational center of gravity. Its throughput will ultimately determine how fast the virtual immune system grows.