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Castle Island Ventures
Castle Island Ventures was founded in 2018 by Nic Carter and Matt Walsh, both of whom previously worked in crypto investing at Fidelity and other firms.
Castle Island Ventures
Castle Island Ventures was founded in 2018 by Nic Carter and Matt Walsh, both of whom previously worked in crypto investing at Fidelity and other firms. The firm operates as a single-family office structure, investing its own capital alongside limited partners in select funds. The firm concentrates on early-stage blockchain infrastructure, including layer-1 protocols, scaling solutions, and decentralized finance platforms. Known portfolio positions include Chainlink, MakerDAO, and Compound. Geographic reach is primarily North America, with some European exposure. Castle Island has also co-invested with firms like Polychain Capital and Paradigm. Castle Island operates with a lean team — fewer than ten professionals — and has no disclosed additional offices. The firm manages two flagship funds; Fund II, raised in 2021, totaled $30M. In 2023, the firm launched a public policy arm, Castle Island Policy, focused on regulatory advocacy. A key differentiator is the principals' deep policy engagement — both Carter and Walsh are prolific writers on crypto regulation, giving the firm an unusual dual posture as both investor and policy shaper. Succession and governance are not publicly detailed, but the firm's long-duration mandate distinguishes it from shorter-cycle crypto funds.
General information
Firm type
Single Family Office
Year founded
2018
AUM
Undisclosed
Location
Region
North America
Country
United States
City
Boston
Corporate office
Boston, MA, United States
Principals
Nic Carter
General Partner
Matt Walsh
General Partner
Sector focus
Frequently asked questions
Who runs investment decisions at Castle Island Ventures?
General Partners Nic Carter and Matt Walsh lead all investment decisions. Carter is known for his research on Bitcoin mining and blockchain analytics; Walsh previously co-founded the crypto investment firm Off the Chain Capital. Both have been active in the space since the early 2010s (public record).
Is Castle Island Ventures structured as a family office or a venture firm?
The firm operates as a single-family office investing its own capital, alongside fund commitments from select LPs. This structure gives it a long-duration, patient capital approach distinct from traditional venture funds (public record).
What investment stages does Castle Island typically target?
The firm focuses on early-stage investments — primarily seed and Series A — in blockchain infrastructure and protocols. It has also participated in later-stage rounds through follow-on investments.
How does Castle Island source proprietary deal flow?
Castle Island's deal flow comes from the principals' deep networks in the crypto ecosystem, built through years of research, writing, and policy engagement. Nic Carter's reputation as a public analyst generates inbound opportunities.
Does Castle Island participate in fund commitments or only direct deals?
Primarily direct venture investments, but the firm has co-invested alongside other crypto-native funds such as Polychain Capital and Paradigm. It also allocates capital to select external funds.
What sectors does Castle Island explicitly avoid?
The firm publicly avoids investments in centralized exchanges, consumer-facing applications, and pure trading strategies. Its thesis is centered on public, permissionless blockchain infrastructure (per public record).
Where does the underlying wealth come from?
The family office backstory is not publicly disclosed. The firm is believed to be funded by private wealth from an undisclosed family, alongside the founders' own capital.
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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