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X/Seed Capital
X/Seed Capital is a San Francisco-based seed-stage firm backing computational-biology and enterprise startups like Ultima Genomics and Septerna.
X/Seed Capital
X/Seed Capital was founded in 2010 by a team of experienced operators and investors who built the firm around a thesis that the most transformative companies need active, technically-informed capital from day one. The partnership structure reflects this — general partners include scientists and engineers who previously founded or led companies at the intersection of computation and biology. The firm maintains a single office in San Francisco, positioning itself within the Bay Area's densest cluster of life sciences and deep tech talent. The firm deploys capital across enterprise software, AI/ML, robotics, digital health, and fintech, with a particular emphasis on companies that apply computational approaches to biological problems. X/Seed typically leads or co-leads seed rounds, with initial checks between $500,000 and $3 million, and reserves significant follow-on capital for subsequent rounds. Confirmed portfolio positions include Ultima Genomics, a next-generation sequencing company that raised $600 million in 2022 (per Bloomberg, 2022), and Septerna, a GPCR-focused drug discovery platform that filed for an IPO in 2024 (per the firm's regulatory filings, 2024). The firm invests primarily in North America, with occasional exposure to European deep tech startups. X/Seed does not publicly disclose assets under management or total deployment, consistent with the partnership's private structure. The firm's team size is not publicly known, though its concentrated portfolio model suggests a lean investment team. No affiliated philanthropic foundations or adjacent operating companies are disclosed. In October 2024, the firm participated in Septerna's $288 million Nasdaq IPO, marking one of the largest biotech public offerings of the year (per Nasdaq, 2024). The firm's structural differentiator is its operator-centric partnership — several partners hold advanced scientific degrees and have founded companies in computational biology and medical devices. This technical depth shapes how X/Seed evaluates early-stage opportunities, particularly in fields where scientific risk and engineering execution are the primary determinants of success. The firm does not operate an external LP advisory network or co-investor club, relying instead on the partnership's direct network and scientific credibility to source deals.
General information
Firm type
Private Equity
Year founded
2010
AUM
Undisclosed
Location
Region
North America
Country
United States
City
San Francisco
Corporate office
San Francisco, CA, United States
Sector focus
Frequently asked questions
What is X/Seed Capital's investment focus?
X/Seed targets early-stage companies applying computational approaches to biology, alongside enterprise software, AI/ML, robotics, and digital health. The firm leads or co-leads seed rounds, writing initial checks typically between $500,000 and $3 million. It reserves capital for follow-on investments through later rounds.
Who makes investment decisions at X/Seed Capital?
The partnership consists of general partners with backgrounds as scientists, engineers, and company founders in computational biology and medical devices. Specific named principals are not publicly disclosed in a consolidated format. Investment decisions are made collectively by the partnership.
Does X/Seed Capital invest only in the United States?
X/Seed primarily invests in North American companies, with its office in San Francisco serving as the hub for sourcing and portfolio support. The firm has made occasional investments in European deep tech startups. No dedicated international offices are publicly disclosed.
How is X/Seed Capital structured as a firm?
X/Seed operates as a private partnership — not a single family office or corporate venture arm. It raises traditional venture funds from institutional limited partners and follows a concentrated portfolio model. The partnership does not disclose fund sizes, AUM, or detailed LP identities.
What are notable X/Seed Capital portfolio companies?
Confirmed positions include Ultima Genomics, a next-generation sequencing company that raised $600 million in 2022 (per Bloomberg, 2022), and Septerna, a GPCR-targeted drug discovery company that completed a $288 million Nasdaq IPO in 2024 (per Nasdaq, 2024). Additional portfolio companies span computational biology, robotics, and enterprise software.
Profile maintained by Altss using OSINT (open-source intelligence), regulatory filings, licensed data partners, and verified direct submissions. Read the methodology. Last updated: . Continuous refresh with full update cycles at least every 30 days.
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