Castle Island Ventures is a venture capital firm. Based in Boston, Massachusetts, United States. Known portfolio companies include Atrium, Valinor, Project Eleven, Birch Hill Holdings, RockSolid Network and XFX, 10 companies in all.
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Investment focus
- Sector
- FinTech
Who to pitch at Castle Island Ventures
Castle Island Ventures portfolio companies (10)
- Atrium
- Valinor
- Project Eleven
- Birch Hill Holdings
- RockSolid Network
- XFX
- Arx
- Gondor
- Cyclops.io
- Tesser
Co-investors
Funds that share portfolio companies with Castle Island Ventures.
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About Castle Island Ventures
The firm's listing covers sector FinTech, and focus areas Blockchain, Crypto, DeFi and NFT; known deals cluster at Pre-Seed, Seed and Series A.
The team counts 5 people in our database. Sean Judge (General Partner) and Matthew Walsh (Founding Partner) are shown as the contacts to pitch.
Castle Island Ventures shares portfolio companies with 20 other investment firms, among them Nascent, Fin Capital and 1kx.
Frequently asked questions
What is Castle Island Ventures?
Castle Island Ventures is a venture capital firm based in Boston, Massachusetts, United States, with a known portfolio of 10 companies. The portfolio comes from public investment records rather than from the firm, so deals that never surfaced publicly are not in it.
What does Castle Island Ventures invest in?
Listed sectors include FinTech; listed focus areas include Blockchain, Crypto, DeFi and NFT. Those tags come from the portfolio attached to the firm, so they describe what has been backed rather than a stated mandate for what comes next.
What stage does Castle Island Ventures invest at?
The known deals of Castle Island Ventures include Pre-Seed, Seed and Series A rounds. Check that against your own round before reaching out: stage mismatch is the most common reason a well matched sector still goes nowhere.
Who should I pitch at Castle Island Ventures?
2 of the 5 people on file at Castle Island Ventures are listed as contacts for the firm. All 5 have their own profile page.
How do I contact Castle Island Ventures?
Any email address on file for the firm is masked on this page and readable inside RaiseHunt after you create an account. The 5 people attached to the firm have their own pages, each showing whether an address is on file for them.
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Data: RaiseHunt investor dataset · Snapshot 5 September 2026 · How this data is built · Report a correction or request removal