/

Investors / Castle Island Ventures / Compare with Chapter One

Castle Island Ventures vs Chapter One

Castle Island Ventures lists 25 portfolio companies and has joined 15 funding rounds; Chapter One lists 76 companies and has joined 7 rounds. Castle Island Ventures comes in most often at Seed (50% of its entries), Chapter One comes in most often at Seed (71% of its entries). 2 companies are on both portfolios, among them Andrena and Erebor.

25Portfolio companies76
15Funding rounds joined7
7Rounds led0
10Rounds, last 12 months4
$5M to $20MTypical round it comes in at$5M to $20M
0%Sites no longer answering0%
Show as a table
Castle Island Ventures and Chapter One, head to head
Castle Island VenturesChapter One
Portfolio companies2576
Funding rounds joined157
Rounds led70
Rounds, last 12 months104
Typical round it comes in at$5M to $20M$5M to $20M
Sites no longer answering0%0%

Where they come in

share of entries by stage
Pre-seed0%0%
Seed50%71%
Series A42%29%
Series B8%0%
Growth0%0%

Castle Island VenturesChapter One

Show as a table
Entry stages of Castle Island Ventures and Chapter One, share of entries
Castle Island VenturesChapter One
Pre-seed0%0%
Seed50%71%
Series A42%29%
Series B8%0%
Growth0%0%

Themes

share of checked companies
Fintech58%21%
AI & Machine Learning3%19%
Cybersecurity11%12%
Crypto & Web311%6%
Education0%8%
Enterprise Software3%8%

Castle Island VenturesChapter One

Show as a table
Themes of Castle Island Ventures and Chapter One, share of checked companies
Castle Island VenturesChapter One
Fintech58%21%
AI & Machine Learning3%19%
Cybersecurity11%12%
Crypto & Web311%6%
Education0%8%
Enterprise Software3%8%

Companies both back

2

Shared companies are those both firms' own portfolio pages list, each checked against the company's site. The same comparison through the API is POST /v1/overlap, for up to 20 firms. How the data is graded

Free account · no card

Compare Castle Island Ventures and Chapter One as data

Pull both portfolios and every co-investor through one API key or MCP, and lay up to 20 firms side by side with POST /v1/overlap. A free account adds Ask AI searches and alerts when either firm adds a company.

Work email, sign-in link by email. Already have an account? Log in
  • Ask AI5 plain-English investor searches a day
  • Full listsEvery portfolio row and two-firm overlap
  • API and MCP100 REST or MCP calls a month, one key
  • AlertsFollow 5 investors for portfolio and fund changes
VCinfo API
$ curl -H "X-API-Key: YOUR_KEY" \
  https://api.vcinfo.io/v1/firms/castleisland.vc/portfolio

# also
GET /v1/firms/chapterone.com/portfolio
GET /v1/firms/castleisland.vc/coinvestors
The same data as an MCP server for Claude, Cursor and other AI tools. Set up MCP · Docs · Pricing