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Investors / Castle Island Ventures / Compare with Y Combinator

Castle Island Ventures vs Y Combinator

Castle Island Ventures lists 25 portfolio companies and has joined 15 funding rounds; Y Combinator lists 5,150 companies and has joined 3,388 rounds. Castle Island Ventures comes in most often at Seed (50% of its entries), Y Combinator comes in most often at Seed (98% of its entries). 3 companies are on both portfolios, among them ARQ, Talos and TRM Labs.

25Portfolio companies5,150
15Funding rounds joined3,388
7Rounds led2,960
10Rounds, last 12 months579
$5M to $20MTypical round it comes in atunder $1M
0%Sites no longer answering0%
Show as a table
Castle Island Ventures and Y Combinator, head to head
Castle Island VenturesY Combinator
Portfolio companies255,150
Funding rounds joined153,388
Rounds led72,960
Rounds, last 12 months10579
Typical round it comes in at$5M to $20Munder $1M
Sites no longer answering0%0%

Where they come in

share of entries by stage
Pre-seed0%0%
Seed50%98%
Series A42%1%
Series B8%0%
Growth0%1%

Castle Island VenturesY Combinator

Show as a table
Entry stages of Castle Island Ventures and Y Combinator, share of entries
Castle Island VenturesY Combinator
Pre-seed0%0%
Seed50%98%
Series A42%1%
Series B8%0%
Growth0%1%

Themes

share of checked companies
Fintech58%13%
AI & Machine Learning3%26%
Healthcare & Biotech3%11%
Cybersecurity11%5%
Crypto & Web311%0%
Enterprise Software3%10%

Castle Island VenturesY Combinator

Show as a table
Themes of Castle Island Ventures and Y Combinator, share of checked companies
Castle Island VenturesY Combinator
Fintech58%13%
AI & Machine Learning3%26%
Healthcare & Biotech3%11%
Cybersecurity11%5%
Crypto & Web311%0%
Enterprise Software3%10%

Companies both back

3

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

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Compare Castle Island Ventures and Y Combinator 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.

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  • 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/ycombinator.com/portfolio
GET /v1/firms/castleisland.vc/coinvestors
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