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The Venture Codex

Castle Island Ventures

1 Broadway Ste 16, Cambridge, Massachusetts, 02142, United States

Overview

They are a venture capital firm focused exclusively on public blockchains. They invest in infrastructure and application companies that will enable these transformative protocols to power services for the next billion users.

Total investments
75
Lead investments
25
Investments · 12mo
11
Active investors
5

Sector focus

  • Venture Capital
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Investment portfolio

  • Birdai Labs

    Led · Seed · Jul 2026

    Birdai Labs develops on-chain transaction infrastructure designed to control transaction timing, ordering, and propagation. The team, founded by former Franklin Templeton employees, is targeting inefficiencies in blockchain networks such as MEV and slippage. Birdai announced a $4 million funding round led by Castle Island Ventures with participation from Metalayer Ventures and The Venture Dept. The company intends to use the capital to advance its infrastructure and tooling around transaction processes. The announcement did not disclose revenue, user metrics, prior financings, or a valuation.

  • Cyclops

    Participated · Series A · Jul 2026

    Cyclops offers an all-in-one stablecoin platform purpose-built for payments companies, providing orchestration and full-stack integrations to enable stablecoin settlement, pay-ins, payouts and treasury optimization via a single API. The company emphasizes end-to-end integrations with leading providers across the stablecoin stack and proprietary technology layered on top to simplify payments use cases. Cyclops claims product and license redundancy in major markets, with dozens of partners and over 100 global licenses. Its founding team includes payments veterans Alex Wilson and Pat Duffy and international technology lawyer David Johnson, who shaped the company’s approach to global licensing. Operational metrics disclosed at the time of the raise include a merchant network of 300,000, 350% month-over-month volume growth, and a headcount of 31 with plans to double by year end. The company plans to use the Series A proceeds to accelerate product development, expand local teams and licensing, and scale its go-to-market efforts.

  • Valinor

    Led · Seed · Mar 2026

    Valinor provides institutional capital solutions encompassing principal investing, capital markets, and advisory at the intersection of credit and blockchain. The firm positions itself to enable 'Open Credit,' a blockchain-enabled infrastructure upgrade intended to reduce friction and cost and expand financing across asset classes, borrowers, and geographies. Valinor combines credit underwriting discipline with digitally-native operations to originate and invest in institutional credit onchain. The company plans to scale through operational development, strategic hires, and capital deployment, and to continue investing alongside institutional partners. Valinor was founded in 2025 by Connor Dougherty and Lily Yarborough and is headquartered in New York.

  • XFX

    Led · Series A · Mar 2026

    XFX has built an “engine” to match buyers and sellers of currency faster, enabling swaps between stablecoins and select fiat currencies. The platform currently supports U.S. dollars, Mexican pesos, and Colombian pesos and aims to create deep liquidity in a subset of currency pairs. Its customers include financial institutions, money transmitters, and crypto exchanges, though the company has not publicly named specific clients. The three cofounders met at Bitso and bring experience from crypto trading and traditional finance. XFX plans to hire more quants and expand relationships with trading desks and banks as it grows. The company was founded in 2025 and is headquartered in Miami.

  • Birch Hill Holdings

    Led · Seed · Feb 2026

    Birch Hill Holdings is an institutional digital asset infrastructure firm that structures on-chain lending strategies and tokenized asset market access for fiduciaries. Its core offering combines traditional credit-market discipline with blockchain settlement efficiencies, anchored by the Birch Hill Collateral Risk Framework that delivers real-time oversight of collateral quality, liquidity conditions, and pricing data integrity. The platform works with institutional service providers for custody, monitoring, identity verification, and audit to ensure a fully compliant operating environment. Birch Hill’s founding team previously built structured credit products at Goldman Sachs and institutional risk systems within BlackRock’s Aladdin platform, later spinning up a digital asset research unit now operating as Birch Hill Labs. With the newly raised capital, the company will grow its technical risk and engineering teams and pursue regulatory registrations needed to serve institutional clients. Initial lending strategies are rolling out through established blockchain lending platforms, with plans to expand into a broader suite of institutional credit offerings tailored to varying compliance and risk requirements. Based in New York, Birch Hill has so far secured $2.5 million in pre-seed funding to fuel these initiatives.

Team