Castle Island Ventures
Castle Island Ventures is a venture capital firm based in Cambridge, United States, focused on Pre-Seed to Series A startups in Crypto & Web3, Fintech, and Payments. This profile covers its focus and how founders can get in front of it in 2026.
- Investment focus
- Crypto & Web3FintechPaymentsCybersecurityDeveloper Tools & Data
- Investment stages
- Pre-SeedSeedSeries A
- Location
- Cambridge, United States
- Founded
- 2018
- Team size
- 1-10
- Portfolio companies
- 76+
- Latest deal on record
- July 2026
About Castle Island Ventures
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.
Source: the organization's public company profile.
How to pitch Castle Island Ventures
The founders who hear back from Castle Island Ventures lead with traction and a clear ask that matches its stage, not a generic mass email. Build a targeted, verified list, write a personalized note, and track who opens it, all in one place.
Connect with Castle Island Ventures
About this profile
This profile is part of Round Funded, an investor database and outreach platform for founders. It covers 60,000+ active VCs, angels, family offices and accelerators with verified contacts, lets you send pitches from your own Gmail, and includes a free Data Room for your raise. How this data is built.
Cite this page
Round Funded. "Castle Island Ventures." Round Funded investor database, updated October 19, 2026.
Stable URL, it will not change: https://www.roundfunded.com/en/vc/castle-island-ventures
Frequently Asked Questions
What does Castle Island Ventures invest in?
Castle Island Ventures focuses on Crypto & Web3, Fintech, Payments, and Cybersecurity. Match your sector and stage before reaching out, then find similar active investors on Round Funded.
What stage does Castle Island Ventures invest at?
Castle Island Ventures focuses on Pre-Seed to Series A rounds. Lead with traction that fits the stage when you reach out.
Is Castle Island Ventures actively investing?
Yes. Round Funded's research found that Castle Island Ventures has made a new investment or run a new cohort since 2024, and its latest deal on record is from July 2026. Reach out with a personalized pitch that fits its stage and focus, then track who opens it.
Where is Castle Island Ventures based?
Castle Island Ventures is based in Cambridge, United States. You can reach out from anywhere with a pitch that matches its focus.
How do I contact Castle Island Ventures?
Unlock a verified email for Castle Island Ventures and reach out with a personalized pitch on Round Funded. We show only deliverable contacts, so your outreach does not bounce.
What is Round Funded?
Round Funded is an investor database and outreach platform for startup founders. It lists 60,000+ active investors with verified contacts, filtered to recent investment activity, and lets founders send personalized pitches from their own Gmail, track replies, and share a free Data Room. Round+ starts at $99 per month with a 3-day trial.