Castle Island Management, LLC
Castle Island Ventures is a venture capital firm investing in public blockchain startups. Explore our mission and portfolio.
In the firm's own words, from its website.
8 additional team members, 25 additional co-investors and affiliates, 24 additional investments, funds and LPs, 18 events, 2 verified contacts (1 general firm email, 1 firm phone)
Every relationship, signal and contact on this record, with the source on each.
Includes 3 days of DFX Intelligence. Then $199/month unless canceled.
What matters now
- 4 companiesnew in 12 months
4 new companies in the last 12 months.
A firm writing cheques this quarter is one a founder can pitch now.
- 2 companiesportfolio raising
2 portfolio companies have new financing on record in 6 months without this firm named on the round; the latest on 2 Jul 2026 ($20M sold on Form D).
A portfolio company raising again is a follow-on decision for the firm and a co-investment opening for others.
- 3 dealswith Coinbase Ventures
Invests most often alongside Coinbase Ventures (3 shared deals) and Variant (2 shared deals).
pair last observed on record 30 Sep 2026, not a deal date · The firms it syndicates with are the likeliest to see the same deals and to fill out its rounds.
Measuredshared rounds and portfolio companies on recordFor Founders building a round, co-investorsCo-investors →
People to know
View all people- Managing MemberWhy: Named with investment responsibilityNo route on file yet
- Managing MemberWhy: Named with investment responsibilityNo route on file yet
- Managing MemberWhy: Named with investment responsibilityNo route on file yet
Relationship network
69 connected entities4 observed rounds1 repeat counterparty2 dated rounds shown here, 2026
From financing rounds and every investor named in them, Form ADV and Form D filings, the firm's funds and team, and disclosed LP commitments in the venture capital graph. A round's amount is the size of the round, not money that moved between two investors.
Some relationships on this record are counted rather than named here. They open with the full profile.
Click any name or line for the rounds and sources behind it. Line weight is rounds together; dashed lines are inferred.
- Sponsor
- Company
- Fund or vehicle
- Person
›How strength and recency are read
Co-investors are read from the rounds: three or more shared rounds is a strong observed relationship, two a repeat co-investor, one a single round. Funds and people are structural. Nothing is scored that a reader cannot check.
Darker lines were active in the last 24 months or are current; lighter lines are older or undated.
How am I connected?
Name your firm, a company or a person, and DFX finds the published routes to Castle Island Management, LLC: a shared portfolio company or board, a prior employer, a co-investor, a shared LP or service provider. Every step is a filed or published record with its source; none is a guess about who knows whom.
See how you connect to Castle Island Management, LLC
Includes 3 days of DFX Intelligence. Then $199/month unless canceled.
Investing
12 companies on record, 4 new in 12 months
Investments on record
What these amounts mean“This investor” is the amount disclosed for this investor alone; it is unknown unless a source said it. The round size is the whole round.Acquired, Public, Exited and Active are what the firm’s own portfolio card says, read on the date shown when you hover the chip; they are not deal dates. A company with no chip is one whose card states no outcome: DFX does not assume it is active.| Company | Round | Role | Partner | Round size | This investor | Date | Source |
|---|---|---|---|---|---|---|---|
| Bitwise | portfolio listing | unknown | unknown | unknown | unknown | Sep 30, 2026 | Fact Firm website |
| Félix | portfolio listing | unknown | unknown | unknown | unknown | Sep 30, 2026 | Fact Firm website |
| Félix Pago | portfolio listing | unknown | unknown | unknown | unknown | Sep 30, 2026 | Fact Firm website |
Stated thesis versus observed behaviour
- Sectors
- crypto
- Stages
- early
- Geography
- not stated
- Check size
- not stated; DFX does not estimate checks from round sizes
- Self-described
- venture capital
Team
15 current, 0 departed
Decision makers
Ranked by the role the firm or its filing states, a route on file and deals led. Every reason is read from the record, never inferred. Routes are published by the person or the firm (their bio, the team page or a filing) and are revealed on a plan; data bought from a provider is never shown, and a route printed at a firm the person has since left is held back.
Investment team
How the team is orderedPartners who lead rounds first (rounds led, then deals attributed, then seniority), then the rest of the investment team, then investor relations, finance and operations. A person named by two sources under two spellings is shown once.- Managing Member
- Managing Member
- Managing Member
2 departed (kept with end dates)
- Sean Judge · General Partner · ? to Sep 30, 2026 Inference
- NIC Carter · Founding Partner · ? to Sep 30, 2026 Inference
Contacts
1 general firm email, 1 firm phone on record, each with its source. Values open with the complete profile.
Funds and LPs
18 vehicles, 0 LPs disclosed
Funds and vehicles
What these amounts meanGAV is the gross asset value the adviser reported on Form ADV for the vehicle, never the fund’s committed size and never dry powder. Form D sold is the amount sold as of the latest filing, never a final close.| Vehicle | Type | Vintage | Lifecycle | Reported GAV | Owners | Form D sold | Latest Form D |
|---|---|---|---|---|---|---|---|
| CIV Opportunity Series Co-Invest I, L.P. - (series 9) | SPV or co-invest vehicle | 2023 adv first reported | Active deployment | $25.9M Mar 31, 2026 | 5 | $0 | Mar 31, 2022 |
| CIV Opportunity Series Co-Invest I, L.P. - (series 8) | SPV or co-invest vehicle | 2023 adv first reported | Active deployment | $8.5M Mar 31, 2026 | 10 | $0 | Mar 28, 2022 |
| CIV Opportunity Series Co-Invest I, L.P. - (series 10) | SPV or co-invest vehicle | 2023 adv first reported | Active deployment | $891,363 Mar 31, 2026 | 3 | unknown | unknown |
Limited partners
Known LPs and allocators
What these amounts and dates areEach commitment is counted once across the pension tape and the allocator graph. A commitment date prints only when the source printed one; otherwise the row carries the report date. A foundation’s 990-PF line is a holding at fair value, never a commitment. Rows without a fund on the venture graph are commitments to this manager.| Allocator | Type | Fund | Amount | Date | Source |
|---|---|---|---|---|---|
| Kenneth Rainin Foundation | FOUNDATION | Castle Island Ventures III, L.P. | $3.3M fair value on the foundation's return | reported as of Dec 31, 2024 | Fact IRS Form 990 / 990-PF e-file returns |
Relationships across DFX
28 co-investors · on 2 other DFX graphs
Co-investors
- 2026-09-303 shared deals · recurring · this firm led 1
- 2026-10-012 shared deals · recurring · this firm led 1
- 2026-09-302 shared deals · recurring
Across DFX and the capital chainon 2 other DFX graphs · 1 capital path ShowHide
- The same institution is held on Allocators, RIA and Wealth, matched by identifier. See which records
Castle Island Management, LLC is the same institution as 2 records in Allocators and RIA and Wealth.
DFX found 2 relationships across 2 datasets
Which record it is in each graph, what it is called there, and how the two were matched.
Includes 3 days of DFX Intelligence. Then $199/month unless canceled.
Checking your plan…
Castle Island Management, LLC sits on 1 traced path of capital across the graphs.
DFX traced 1 path of capital through this record
Every record on each path, what it committed or lent, and as of when.
Includes 3 days of DFX Intelligence. Then $199/month unless canceled.
Derived from allocator disclosures, BDC schedules and SEC filings; confidence is the weakest hop.
Checking your plan…
Evidence and history
23 dated events, 64 observations from 3 sources
Timeline
- Mar 31, 2026Castle Island Ventures IV, LP first reported on Form ADV by Castle Island Management, LLC (Venture Capital Fund), GAV $143,300,000
- Mar 31, 2026Castle Island Ventures IV Feeder, LP first reported on Form ADV by Castle Island Management, LLC (Venture Capital Fund), GAV $26,100,000
- Sep 29, 2025Castle Island Management, LLC filed the first Form D for Castle Island Ventures IV, L.P. (fund 4), its next fund after Castle Island Ventures III, L.P. (vintage 2022)
- Mar 29, 2023CIV Opportunity Series Co-Invest I, L.P. - (series 10) first reported on Form ADV by Castle Island Management, LLC (Venture Capital Fund), GAV $450,000Fund first reported on Form ADVFundsFactCIV Opportunity Series Co-Invest I, L.P. - (series 10)Form ADV
- Mar 29, 2023CIV Opportunity Series Co-Invest I, L.P. - (series 9) first reported on Form ADV by Castle Island Management, LLC (Venture Capital Fund), GAV $9,033,971Fund first reported on Form ADVFundsFactCIV Opportunity Series Co-Invest I, L.P. - (series 9)Form ADV
Identity and regulatory footprint
Address, phone, Form ADV filing and ownersForm ADV filed Mar 31, 2026 · 16 private fundsShowHide
- Headquarters
- Boston, MAadviserinfo.sec.gov
- Office address
- unknownadviserinfo.sec.gov
- Business phone
- unknownadviserinfo.sec.gov
- Website
- castleisland.vc
- SEC adviser type
- Exempt reporting adviseradviserinfo.sec.gov
- SEC exemption claimed
- Venture capital fund adviseradviserinfo.sec.govItem 2.B(1): advises solely venture capital funds
- Latest Form ADV
- Mar 31, 2026
- Private funds reported
- 16 (16 venture capital funds)adviserinfo.sec.gov
- Private fund gross assets, adviser total
- $790Madviserinfo.sec.govreported GAV of the funds, the adviser's own number; not fund size, not dry powder
Classification history
Classification history
Every classification this record has carried4 on recordShowHide
- Sep 23, 2026Institutional venture firm (confirmed, 95%)Venture manager, reported GAV $790M across 18 vehicles
- Sep 15, 2026Institutional venture firm (confirmed, 95%)Venture manager, reported GAV $542M across 18 vehicles
- Sep 12, 2026Institutional venture firm (confirmed, 95%)Venture manager, reported GAV $542M across 17 vehicles
- Sep 12, 2026Institutional venture firm (confirmed, 95%)Venture manager, reported GAV $542M across 15 vehicles
Evidence
Every observation behind this profile, with its source, date and class
| Fact | Value | Effective | Class | Source |
|---|---|---|---|---|
| Why admitted | VC exemption, VC funds reported | Mar 31, 2026 | Fact | Form ADV |
| SEC exemption claimed | Venture capital fund adviser | Mar 31, 2026 | Fact | Form ADV |
| SEC exemption claimed | Venture capital fund adviser | Mar 29, 2024 | Fact | Form ADV |
| SEC adviser type | Exempt reporting adviser | Mar 31, 2026 | Fact | Form ADV |
| SEC adviser type | Exempt reporting adviser | Mar 31, 2026 | Fact | Form ADV |
| SEC adviser type | Exempt reporting adviser | Mar 29, 2024 | Fact | Form ADV |
| First Form ADV filing | 2018-10-12 | Mar 31, 2026 | Fact | Form ADV |
| First Form ADV filing | 2018-10-12 | Mar 29, 2024 | Fact | Form ADV |
| Adv history loaded | adv-hist-1+panel:2026-09-30 | Oct 1, 2026 | Fact | Form ADV |
| Adv history loaded | adv-hist-1+panel:2026-09-29 | Sep 30, 2026 | Fact | Form ADV |
| Adv history loaded | adv-hist-1+panel:2026-09-25 | Sep 26, 2026 | Fact | Form ADV |
| Adv history loaded | adv-hist-1+panel:2026-09-23 | Sep 24, 2026 | Fact | Form ADV |
| Adv history loaded | adv-hist-1+panel:2026-09-21 | Sep 23, 2026 | Fact | Form ADV |
| Adv history loaded | adv-hist-1+panel:2026-09-22 | Sep 23, 2026 | Fact | Form ADV |
| Adv history loaded | adv-hist-1 | Sep 12, 2026 | Fact | Form ADV |
| Latest Form ADV filing | 2026-03-31 | Mar 31, 2026 | Fact | Form ADV |
| Latest Form ADV filing | 2026-03-31 | Mar 31, 2026 | Fact | Form ADV |
| Latest Form ADV filing | 2024-03-29 | Mar 29, 2024 | Fact | Form ADV |
| SEC status | ERA - Active | Mar 31, 2026 | Fact | Form ADV |
| SEC status effective | 2018-10-12 | Mar 31, 2026 | Fact | Form ADV |
| Venture share of reported funds | 1 | Mar 31, 2026 | Fact | Form ADV |
| Venture share of reported funds | 1 | Mar 29, 2024 | Fact | Form ADV |
| Business phone | Mar 31, 2026 | Fact | Form ADV | |
| Business phone | Mar 29, 2024 | Fact | Form ADV | |
| Contact page url | Sep 30, 2026 | Fact | ||
| Contact page url | Sep 16, 2026 | Fact | ||
| Description | Sep 30, 2026 | Fact | ||
| Description | Sep 16, 2026 | Fact | ||
| Description | Sep 15, 2026 | Fact | ||
| Headquarters | Boston, MA | Mar 31, 2026 | Fact | Form ADV |
| Headquarters | Hingham, MA | Mar 29, 2024 | Fact | Form ADV |
| Office address | Mar 31, 2026 | Fact | Form ADV | |
| Office address | Mar 29, 2024 | Fact | Form ADV | |
| Self-described type | Venture capital “We are a venture capital firm” | Sep 30, 2026 | Fact | |
| Self-described type | Venture capital “We are a venture capital firm” | Sep 16, 2026 | Fact | |
| Self-described type | Venture capital “We are a venture capital firm” | Sep 15, 2026 | Fact | |
| Legal form | Limited Liability Company | Mar 31, 2026 | Fact | Form ADV |
| Legal form | Limited Liability Company | Mar 29, 2024 | Fact | Form ADV |
| Portfolio page | Sep 30, 2026 | Fact | ||
| Portfolio page | Sep 16, 2026 | Fact | ||
| Portfolio page | Sep 15, 2026 | Fact | ||
| Private funds reported | 16 | Mar 31, 2026 | Fact | Form ADV |
| Private funds reported | 16 | Mar 31, 2026 | Fact | Form ADV |
| Private funds reported | 16 | Mar 29, 2024 | Fact | Form ADV |
| Private fund gross assets (reported) | $790M | Mar 31, 2026 | Fact | Form ADV |
| Private fund gross assets (reported) | $790M | Mar 31, 2026 | Fact | Form ADV |
| Private fund gross assets (reported) | $542M | Mar 29, 2024 | Fact | Form ADV |
| Schedule a diff | sadiff-1 | Mar 31, 2026 | Fact | Form ADV |
| Stated sectors | crypto “sector words on the home page” | Sep 30, 2026 | Fact | |
| Stated sectors | crypto “sector words on the home page” | Sep 16, 2026 | Fact | |
| Stated sectors | crypto “sector words on the home page” | Sep 15, 2026 | Fact | |
| Stated stages | early “stage words on the home page” | Sep 30, 2026 | Fact | |
| Stated stages | early “stage words on the home page” | Sep 16, 2026 | Fact | |
| Stated stages | early “stage words on the home page” | Sep 15, 2026 | Fact | |
| Team page | Sep 30, 2026 | Fact | ||
| Team page | Sep 16, 2026 | Fact | ||
| Team page | Sep 15, 2026 | Fact | ||
| Venture funds reported | 16 | Mar 31, 2026 | Fact | Form ADV |
| Venture funds reported | 16 | Mar 31, 2026 | Fact | Form ADV |
| Venture funds reported | 16 | Mar 29, 2024 | Fact | Form ADV |
| Website | Mar 31, 2026 | Fact | Form ADV | |
| Website | Mar 29, 2024 | Fact | Form ADV | |
| Site title | Sep 30, 2026 | Fact | ||
| Site title | Sep 16, 2026 | Fact | ||
| Site title | Sep 15, 2026 | Fact |
How this is scored
Scores, classification basis and filing advisersInstitutional venture firm, confirmedShowHide
Venture manager, reported GAV $790M across 18 vehicles
- importance
- gav: 0.57 · funds: 1 · people: 0.56 · investments: 0.41 · co investors: 0.58
- active deployment
- investments 12m: 0.5 · fund raising 18m: 0 · people joined 12m: 0 · vintage within 3y: 1 · latest investment at: 2026-07-15
- emerging manager
- fund count: 18 · reported gav: $790M · first adv filing: 2018-10-12 · years since first filing: 8
Fits, record history and connections
scored matches for this investor, every identity change, every edge
Record history
- Merged in2026-09-13
- Adviser's first ADV filing2018-10-12source on record
The ledger records every merge, rename and reclassification this record went through and the dated filings observed on it, so the identity on this page can be traced to the records it was built from. The ledger's own sentences name other records, so they show with the names.