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Castle Island Ventures — Portfolio

Investor actively backing innovative startups and growth-stage companies across various industries and funding rounds.

106
Companies
$997.4M
Total invested
$12.8M
Avg. check
49
Industries
Blockchain 14Cryptocurrency 9FinTech 7Financial Services 5Decentralized Finance (DeFi) 4Software 4+43 more
Founder contacts

Verified emails & LinkedIn for founders across this portfolio.

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Portfolio companies

Showing 124 of 106
Capsule Social
September 2022

A decentralized social media network for unbiased and open discourse, resistant to takedowns and censorship.

Blockchain · Paris$102K Equity Crowdfunding
Stable
September 2025

Stable is a blockchain for digital dollar settlement with gas-free peer transfers.

Blockchain · Carson CityVenture - Series Unknown
Gondor
August 2025

Gondor is a DeFi startup that builds tools to make prediction markets more efficient.

Blockchain · New York$2.5M Pre-Seed
SatLayer
August 2024

SatLayer is the economic layer for Bitcoin, making the best asset now fully programmable.

Bitcoin · Singapore$8.0M Pre-Seed
Pear Protocol
July 2025

Pear Protocol is a decentralised Pairs Trading Exchange.

Blockchain · London$4.1M Seed
Eterneva
July 2021

Eterneva is a developer of diamond technology intended to convert cremated ashes of loved ones into memorial diamonds.

Jewelry · Kerrville$10.0M Series A
Notabene
July 2026

Notabene is the leading institutional transaction and payment messaging network for compliant stablecoin payments and crypto transactions

Blockchain · New York$11.5M Corporate Round
Halborn
July 2022

Halborn is a cybersecurity company protecting blockchain organizations from cyber attacks.

Blockchain · Miami$90.0M Series A
Cyclops.io
July 2026

Cyclops.io is a new operating system for team collaboration.

Information Technology · Miami$20.0M Series A
Mash
June 2022

Mash is a artificial intelligence company that provides knowledge Agents for Technical B2B Revenue and GTM teams.

Artificial Intelligence (AI) · Toronto$6.0M Seed
Groma
June 2023

Groma is launching GromaCoin, an on-chain asset backed by real estate.

Blockchain · Boston$1.0M Venture - Series Unknown
Try Your Best
June 2025

Try Your Best is a blockchain technology company.

Blockchain · Tucson$11.0M Series A
Attestiv
May 2026

Attestiv is an AI software platform that verifies the authenticity of digital media and data for businesses.

Artificial Intelligence (AI) · Lehi$834K Debt Financing
ZenLedger
May 2022

ZenLedger analyzes and simplifies cryptocurrency taxes to help investors and tax professionals in portfolio management.

Accounting · Bellevue$15.0M Series B
evaluate.xyz
May 2022

Trade NFTs on Flow. Search for trading partners, swap NFTs, and shop across marketplaces.

Analytics · Cambridge$4.0M Seed
EasyBins
May 2022

EasyBins is an online retail platform used to offer free grocery delivery.

Delivery Service · Springdale$2.4M Seed
Eaglebrook Advisors
April 2022

Eaglebrook Advisors is a crypto-focused investment firm.

Bitcoin · Miami$2.0M Series A
SoundMint
April 2022

SoundMint is a Web3 & Music incubator.

Blockchain · Los Angeles$1.7M Seed
Ellis
April 2022

Ellis is a modern immigration law firm for startups and growing companies.

Consulting · New York$5.6M Seed
Socket Supply
April 2022

Socket Supply creates tools that help developers deploy to the cloud and beyond.

Internet · New York$3.5M Seed
Valinor
February 2026

Valinor is a digital investment firm that offers flexible financial capital for fintech companies.

Finance · New York$25.0M Seed
Birch Hill Holdings
February 2026

Birch Hill Holdings provides institutional digital asset infrastructure for onchain lending and tokenized asset markets.

Asset Management · West New York$2.5M Pre-Seed
Build on Bitcoin
August 2025

Build on Bitcoin is a hybrid Layer-2 network Bitcoin blockchain

Bitcoin · George Town$9.5M Venture - Series Unknown
Beam
May 2025

Beam is a payment service that uses stablecoins to help people send money globally faster and cheaper.

Cryptocurrency · San Francisco$7.0M Venture - Series Unknown

Where Castle Island Ventures invests

Blockchain14
Cryptocurrency9
FinTech7
Financial Services5
Decentralized Finance (DeFi)4
Software4

About Castle Island Ventures's portfolio

How many companies has Castle Island Ventures invested in?

Castle Island Ventures has invested in 106 companies tracked in our database. The portfolio spans multiple industries and funding stages, from seed-stage startups to late-stage companies.

What industries does Castle Island Ventures invest in?

Castle Island Ventures's top investment sectors include Blockchain, Cryptocurrency, FinTech, Financial Services, Decentralized Finance (DeFi). The firm invests across 49 different industry categories.

What is Castle Island Ventures's largest investment?

Among tracked funding rounds, Halborn received $90.0M in a Series A round. Castle Island Ventures's total known invested capital is $997.4M.

What is the average investment size for Castle Island Ventures?

Castle Island Ventures's average investment size is $12.8M across its portfolio of 106 companies.

What are Castle Island Ventures's most recent investments?

Recent Castle Island Ventures portfolio additions include Capsule Social, Stable, Gondor, SatLayer, Pear Protocol. These companies were founded in 2020 or later.

Reach the founders behind these 106 companies
Verified emails and LinkedIn profiles, updated monthly.
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