Updated: June 13, 2026

Investment Fund
Venture Capital Firm
Web3
Crypto
Castle Island Ventures
Founded 2018 · Cambridge, UK
We are a venture capital firm focused exclusively on public blockchains.
Total investments
61
Successful exits
2
About the program
Program type
Investment stage
Description
Early-stage investor (writes $250k–$1M checks) focused on equity-only Bitcoin and public-blockchain companies, differentiated by ex-Fidelity expertise and research, podcast, and stablecoin reports connecting founders to banks and ETF issuers.
Founded2018
Location
Investment offer
Check size$100 – $10,000,000
Can lead rounds
Yes
Lead preference
Sometimes
Details
Avg Check: $100K - $5M ·
Funding requirements
We invest in various sectors.