Investor Profile: Castle Island Ventures — Thesis, Cheque Size & How to Apply

Learning how to get funding from Castle Island Ventures means understanding its one-rule filter: public blockchains only. This Boston-area firm does not chase every crypto trend. It backs companies building on open, permissionless networks, in monetary networks, financial services and internet infrastructure.

Thesis: a rules-based monetary order

Castle Island Ventures believes public blockchains represent a paradigm shift in how people interact with money, financial services and the internet. In announcing its third fund, it framed the opportunity as a monetary transition towards a rules-based monetary order, visible both in non-sovereign networks like Bitcoin and Ethereum and in the rapid rise of stablecoins, which give savers a free choice of currency, in many cases for the first time. It also backs a more programmable, less intermediated financial system and Web3 architecture built on digital property rights.

Sectors and stages

The firm invests at the early stage in infrastructure and application companies that will let transformative protocols power services for the next billion users. In practice that means stablecoin payments, institutional crypto infrastructure, tokenised assets and blockchain intelligence.

Fund size and cheque size

Castle Island Ventures has raised three funds on a steadily larger scale. Its first fund, launched in 2018, was $30 million. Its second fund was $50 million. Castle Island Ventures III, announced as a $250 million venture fund, supports its mission to partner with entrepreneurs building transformative companies powered by public blockchains. No standard cheque size is publicly disclosed. It led a $20 million Series A for Project 11 in January 2026, a post-quantum security company for crypto.

Notable portfolio

Its current portfolio page names Bitwise, a crypto asset manager; Erebor, a stablecoin-native digital bank; Felix, a stablecoin-powered financial companion for Latino users; Yellow Card, pan-African stablecoin payments; TRM Labs, a blockchain intelligence platform; Talos, an institutional crypto trading platform; Hidden Road Partners, institutional prime brokerage and clearing; Station70, digital asset security and recovery; Project 11, post-quantum security for crypto; and ARQ, digital dollar accounts for Latin America. Earlier portfolio names include BlockFi, CoinMetrics, MoonPay and River Financial.

Partners and team

Castle Island Ventures was founded in 2018 by Matt Walsh and Nic Carter, who previously led a number of early-stage blockchain efforts at Fidelity Investments. Ria Bhutoria, formerly director of research at Fidelity, joined as a general partner around the third fund. The firm's limited partner base for its third fund spans endowment, foundation, asset management, insurance, family office and fund-of-funds investors.

Programs run, credits and perks

Castle Island Ventures runs no public accelerator, no token launch programme and no published credits or perks catalogue. Its support is research depth, regulatory and market-structure understanding, and an institutional network across crypto and traditional finance. Founders should not expect token marketing support or exchange listing promises from this firm.

How to apply for funding

No public application portal for Castle Island Ventures was found in the sources read for this profile. The firm's official site, at castleisland.vc, is the route for contact, and the practical path is a warm introduction through a portfolio founder, a crypto investor or a Fidelity-era contact, with a thesis-fit pitch: the public blockchain, the financial problem, the regulatory path, and why an open network beats a closed one.