Castle Island Ventures
UnclaimedAt a Glance
- Check Size
- $100K – $5M
- Stage
- Pre-Seed, Seed, Series A, Series B+
- AUM
- $75M
- Sectors
- Aerospace & Defense, Other, Consumer +2
- Founded
- 2017
- HQ
- Cambridge, MA
About Castle Island Ventures
Castle Island Ventures is a venture capital firm based in Team Portfolio Writing. The firm focuses on Pre-Seed, Seed, Series A, Series B+ investments across sectors including Aerospace & Defense, Other, Consumer, Fintech, Climate.
Investment Thesis
“Invests in early-stage companies building on blockchain and crypto infrastructure, focusing on the financial services transformation enabled by digital assets.”
Sector Focus
Investment Stage
Notable Portfolio Companies
SEC Fund Filings
- Vehicles filed, last 24 months
- 2
- Latest filing
Castle Island Ventures filed a Form D for 2 fund vehicles between Sep 26, 2024 and Sep 25, 2026.
| Fund vehicle | Source |
|---|---|
| Castle Island Ventures IV Feeder, L.P. | SEC Form D, filed |
| Castle Island Ventures IV, L.P. | SEC Form D, filed |
A Form D is the notice a fund files with the SEC when it raises money in a private offering. Feeder funds, parallel funds and SPVs each file their own, so the count measures filing activity, not the number of flagship funds.
Source: SEC EDGAR Form D filings for pooled investment funds, original filings only (amendments excluded). Our filing data starts Jul 1, 2024. Vehicles are matched to Castle Island Ventures by fund name and checked against the sponsor address and named principals on each filing; offering amounts are not shown. Each “SEC Form D” link opens an EDGAR full-text search for that vehicle’s exact name, where the filing itself is listed. See every new fund filing on the Form D Radar.
Team (4)
Frequently Asked Questions
What stage does Castle Island Ventures invest at?
Castle Island Ventures primarily invests at the Pre-Seed, Seed, Series A, Series B+ stages. This means they focus on companies that are at the earliest idea or prototype phase.
Where is Castle Island Ventures located?
Castle Island Ventures is headquartered in Cambridge, MA. Many of their portfolio companies are also based in this region, though they invest across geographies.
What sectors does Castle Island Ventures focus on?
Castle Island Ventures focuses on investments in Aerospace & Defense, Other, Consumer, Fintech, Climate. Their portfolio reflects deep expertise and networks within these sectors.
What is Castle Island Ventures's typical check size?
Castle Island Ventures's typical investment check size ranges from $100K to $5M. Actual amounts may vary based on the stage, sector, and specific opportunity.
How much does Castle Island Ventures have under management?
Castle Island Ventures manages approximately $75M in assets under management (AUM) across their funds.
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