Castle Island Ventures
50
companies
226
Jobs
Showing 50 companies
Blockchain and Crypto
Finance
Software
1 - 10 employees

Alkimiya Protocol builds capital markets for blockspace. They allow consensus producers to hedge or monetize the premium on cash flow from blockspace and use the cash flow accrued from blockspace as financial legos to construct yield sources.

11 - 50 employees
Seed

Alpen Labs is a startup scaling bitcoin with zero-knowledge technology. Its mission is to build universal rails for money by creating a scalable, private and programmable Bitcoin ecosystem.

Hardware
Mobile, Platforms, and Apps
Telecommunication
11 - 50 employees
Series A

Andrena is a developer of an internet distribution platform designed to offer high-speed internet at reduced costs.The company works directly with internet providers who provide internet for universities, hospitals, financial services and other users with heavy data needs and leverage their existing fiber networks to deploy a series of antennas to blanket a geography with internet access, allowing customers and businesses to tap into a faster network wirelessly.

Blockchain and Crypto
Finance
Software
1 - 10 employees
Seed

Ansible Labs' platform, Beam, connects blockchains and bank accounts. Their mission is to modernize money movement. It was founded in 2022.

Blockchain and Crypto
Finance
Internet Services
Software
1 - 10 employees
Series A

Arcade provides an infrastructure layer for NFT liquidity that enables the financialization of non-fungible assets, non-fungible tokens, or NFTs.Arcade’s Wrapped NFT technology allows NFTs to be bundled to secure one loan. Arcade is also an open-source Defi primitive it allows developers to build on top of the platform.

Finance
Lending and Investments
11 - 50 employees
Seed

Arch is a financial technology company that offers loans to alternative asset owners.

Finance
Professional Services
Security
Software
11 - 50 employees

Attestiv puts authenticity back into photos, videos and documents by utilizing advanced technologies in mobile, AI and blockchain. Attestiv products create new efficiencies, offer unrivaled fraud prevention and maintain interoperability with existing infrastructure.

Babylon
Babylon
7 jobs

At Babylon, we envision a future where Bitcoin and Proof-of-Stake (PoS) chains thrive together. Our mission is to build a Bitcoin-driven decentralized world by evolving Bitcoin into a trusted security backbone for PoS chains, delivering yields for bitcoin holders while fostering an integrated, secure, and decentralized economy. We trace our genesis to a transformative research paper on Bitcoin security, an original work co-authored by our co-founders, David Tse and Fisher Yu, the founder of EigenLayer, Sreeram Kannan and co-authors. Their combined intellect and foresight have set the cornerstone of Babylon. In a testament to our dedication to advancing the field, our research paper has been accepted by the highly-respected 2023 IEEE Symposium on Security and Privacy - a significant global platform for security discourse. The project is led by a team of consensus protocol researchers from Stanford and experienced layer 1 engineers from around the world. Babylon’s mission is to scale Bitcoin to secure the decentralized world. To achieve this, Babylon utilizes the three primary facets of Bitcoin: Bitcoin as an asset, its reliable timestamping service, its most censorship-resistant blockspace in the world. To leverage these facets, Babylon is developing three innovative security-sharing protocols: Bitcoin Staking Protocol, Bitcoin Timestamping Protocol, and Bitcoin Data Availability Protocol. Through these pioneering protocols, Babylon envisions a more secure and decentralized future.

Blockchain and Crypto
Finance
Lending and Investments
Software
51 - 200 employees
Series B

Bitwise Asset Management is a trusted partner to individuals, wealth managers, family offices, investment managers, and institutions in navigating cryptocurrency. Bitwise develops funds, indexes, insight, and other services. The team behind Bitwise has backgrounds in technology, security, and finance.

BOB
BOB
3 jobs

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

Casa
Casa
1 jobs

Casa is a company that offers secure storage solutions for Bitcoin and Ethereum. They provide self custody options, allowing users to take control of their cryptocurrency, hold their private keys, and safely withdraw their crypto from exchanges. Casa o...

Consumer Products
Hardware
Security
11 - 50 employees
Seed

CAT Labs is developing cybersecurity and digital asset recovery solutions to assist governments in combating cryptocurrency crime and protecting investors from scams, fraud, and hacking.