Castle Island Ventures Research
Investment Thesis
Castle Island Ventures is a specialized venture capital firm exclusively focused on public blockchains and cryptoassets. Founded in 2018 by Fidelity alums Nic Carter and Matt Walsh, the firm partners with entrepreneurs building transformative companies powered by public blockchain technologies. The firm believes that public blockchains represent a paradigm shift in how we interact with money, financial services, and the internet itself.
Core Investment Themes
Castle Island invests across three major themes:
Monetary Networks: The firm sees an ongoing monetary transition towards rules-based monetary systems. This includes infrastructure on both non-sovereign networks like Bitcoin and Ethereum, as well as the rapid emergence of stablecoins that give savers worldwide free choice of currency. Their extensive research on stablecoins as emerging market infrastructure demonstrates deep conviction in this thesis.
Financial Services Infrastructure: Castle Island envisions a financial system that is more programmable, transparent, less politicized, and less intermediated. They support companies building DeFi protocols, financial market infrastructure, and lending solutions that disrupt legacy financial services. They explicitly note that traditional financial services firms failing to evolve will face disruption similar to what happened to newspapers with the web.
Internet Architecture (Web3): In parallel with monetary and financial transformation, the firm believes decentralized internet topologies will prove commercially superior to centralized models. They support projects restoring digital property rights, enabling new business models, and disrupting data monopolies.
Portfolio & Recent Activity
As of January 2026, Castle Island has invested in 76+ companies with 9 new investments in the last 12 months. Notable recent activity includes:
- January 2026: Led $20M Series A in Project Eleven (quantum-resistant digital asset infrastructure) at $120M valuation
- January 2026: Invested in Chakra (database software for blockchain)
- December 2025: Invested in Sova
- September 2025: Led $2.8M pre-seed in RockSolid (liquid staking/vaults)
Portfolio includes unicorns: Talos, Crusoe Energy, MoonPay. Early investor in BlockFi, Bitwise, River Financial with successful track records.
Fund History & Assets Under Management
Castle Island has raised three funds:
- Fund I: Early fund establishing blockchain thesis
- Fund II: $50M (announced 2019-2020)
- Fund III: $250M (announced February 2022, currently actively deploying)
Current AUM of approximately $250M+ is actively deployed in early-stage public blockchain companies. The fund has a diversified LP base including endowments, foundations, asset managers, insurers, family offices, and fund-of-funds.
Team & Leadership
The firm is led by four General Partners with complementary expertise:
Nic Carter (Founding Partner): Former Fidelity cryptoasset analyst and Coin Metrics cofounder. Carter is known as a thought leader on blockchain policy and brings deep understanding of monetary systems and stablecoins.
Matthew Walsh (Founding Partner): Led Fidelity's blockchain and cryptoasset initiatives before founding Castle Island. Walsh brings institutional finance experience and board-level governance expertise.
Sean Judge (General Partner): Former Principal at Highland Capital Partners. Focus on financial market infrastructure, consumer fintech, and new blockchain applications. Economics background from Vanderbilt.
Ria Bhutoria (General Partner, recently promoted): Former Director of Research at Fidelity Digital Assets and Senior Research Analyst at Circle. Brings deep expertise in Bitcoin, digital assets, and research infrastructure.
Additional team includes Richard Sgalardi (General Partner, crypto trading background), plus investors and venture partners with expertise in blockchain infrastructure, fintech, and institutional finance.
Investment Strategy & Approach
Stage Focus: Primarily Seed and Series A, with selective pre-seed and later-stage participation
Check Size: $100K to $5M typical range, with capacity for larger allocations and reserves for follow-ons
Decision Making: Partnership model where individual partners have meaningful investment authority, enabling fast decision-making
Founder Preferences: Technical founders with blockchain/cryptoasset expertise, shipping experience, regulatory understanding, and mission-driven approaches
Typical Involvement: Board seats, active partnerships, and ongoing operational support
Sector & Thesis Preferences
Castle Island's exclusive focus on public blockchains means they invest in:
- Bitcoin infrastructure and applications
- Ethereum and EVM-compatible chain innovations
- Layer 2 solutions and rollup technology
- Stablecoins and monetary infrastructure
- DeFi protocols and financial primitives
- Blockchain scaling and performance
- Bitcoin restaking and security solutions
- Enterprise blockchain applications
They explicitly avoid gambling/casino games, speculative-only assets, and proof-of-work mining operations.
Thought Leadership & Content
Castle Island is highly active in thought leadership:
- "On the Brink" podcast with 680+ episodes exploring blockchain and crypto topics
- Regular research whitepapers (e.g., "Stablecoin Payments from the Ground Up" - June 2025)
- Published perspectives on emerging markets, Bitcoin security, stablecoins, and regulation
- Monthly newsletter with market insights
- Strong voices: Nic Carter particularly influential in blockchain policy discussions
Portfolio Companies (Representative Sample)
Alkimiya, Alpen Labs, Andrena, Arcade, Arch, Asymmetry Finance, Atrium, Attestiv, Babylon Labs, Beam, BlockFi, Bitwise, River Financial, Talos, Crusoe Energy, MoonPay, Project Eleven, RockSolid, and 58+ additional companies
Market Position
Castle Island Ventures holds the position of one of the earliest and most respected blockchain-focused venture capital firms. The combination of Fidelity heritage, technical depth, thoughtful thesis, and active engagement with entrepreneurs and policy makers makes them a leading voice in blockchain investment and governance.