Castle Island Ventures
54
companies
213
Jobs
Showing 54 companies
Blockchain and Crypto
Finance
Software
1 - 10 employees

Alkimiya is a decentralized blockspace market protocol that enables users to trade synthetic blockspace resources, such as BTC Transaction Feerate and Base L2 Gas. By addressing the volatility of transaction fees, Alkimiya aims to enhance user experience and promote the adoption of blockchain technologies. The protocol represents a significant advancement in the on-chain economy, allowing consensus producers to hedge or monetize cash flow from blockspace, thereby creating new financial opportunities. As global commerce increasingly integrates on-chain activities, Alkimiya positions itself as a key player in the emerging market for blockspace resources.

11 - 50 employees

Alpen Labs is a startup focused on expanding global financial access through zero-knowledge (ZK) technology on Bitcoin. They are building a modular rollup layer called Strata, which enhances programmability and scalability for Bitcoin-based financial systems. Their mission emphasizes financial inclusion and equal access, particularly in developing regions, by creating a native set of financial rails that leverage Bitcoin's security and infrastructure. Alpen Labs aims to democratize access to financial opportunities, partnering with like-minded organizations to realize this vision.

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

Andrena is a wireless Internet company founded in 2017, providing high-speed Internet to multi-tenant buildings, businesses, and local households at a fraction of the cost. The company aims to revolutionize Internet access by offering affordable connectivity through an innovative delivery method, ensuring stellar customer experience. Andrena believes that Internet access is a fundamental human right and is committed to breaking down barriers to create a more connected and equitable future for all. With plans up to 1 Gbps and a focus on customer satisfaction, Andrena is positioned to disrupt traditional Internet service providers.

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

Arcade is the leading lending platform for NFTs, enabling users to borrow using NFTs on Ethereum and Base. It offers a unique peer-to-peer DeFi protocol that allows for custom loan terms and instant borrowing, enhancing liquidity for NFT owners while providing lenders with yield opportunities. With a total volume of over $272 million and 591 active loans, Arcade stands out in the decentralized finance space by supporting a wide range of assets, including memecoins and ERC20 tokens, making it a versatile platform for both borrowers and lenders.

Finance
Lending and Investments
11 - 50 employees
Seed

Arch is a financial technology company focused on providing secure, reliable, and effortless financial products, particularly crypto-backed loans, to alternative asset investors. Founded by long-term crypto investors, Arch aims to address the shortcomings of traditional financial institutions by offering a fully automated lending platform with a strict no-rehypothecation policy, ensuring that customer assets are safeguarded with bank-grade security. The company emphasizes exceptional customer service and aims to be the leading provider in the crypto financial services sector, backed by significant funding to accelerate its growth.

Finance
Professional Services
Security
Software
11 - 50 employees

Attestiv develops an AI-powered digital media validation platform to reduce risk while improving the customer experience. Attestiv they are providing validation for all digital media with their platform and APIs for insurance and analysis, it scans existing photos, videos, or documents and determines if they are fraudulent.

Babylon
Babylon
8 jobs

Babylon Labs focuses on Bitcoin security-sharing protocols with a vision of building a Bitcoin-secured decentralized world. The latest software development is the world's first trust less and self-custodial Bitcoin staking protocol, which enables Bitcoin holders to stake their BTC on other decentralized systems such as PoS chains, L2s, Data Availability (DA) layers, etc, enabling stakers to earn staking rewards without the need for third-party custody, bridge solutions, or wrapping services. The greater idea is to combine the high security and wide adoption of Bitcoin with the efficiency and scalability of PoS systems, increasing Bitcoin's utility.

Beam connects stablecoins to traditional bank accounts & payment networks. Their mission is to modernize money movement to unleash the internet's full potential to grow GDP.

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

Based in San Francisco, Bitwise is one of the largest and fastest-growing crypto asset managers. The firm is known for managing the world’s largest crypto index fund (OTCQX: BITW) and pioneering products spanning Bitcoin, Ethereum, DeFi, and crypto-focused equity indexes. Bitwise partners with financial advisors and investment professionals to provide quality education and research. The team at Bitwise combines expertise in technology with decades of experience in traditional asset management and indexing, coming from firms including BlackRock, Blackstone, Meta, and Google, as well as the U.S. Attorney’s Office. Bitwise is backed by leading institutional investors and asset management executives, and has been profiled in Institutional Investor, CNBC, Barron’s, Bloomberg, and The Wall Street Journal.

BOB
BOB
2 jobs

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

Blockchain and Crypto
Finance
Security
Software
51 - 200 employees
Series A

Casa was founded to help people own, secure, and manage their private keys safely and easily – without worry if they’re doing it right. We help people secure their digital wealth with more than one private key. That means making a single mistake doesn’t result in lost funds. Casa members can choose from a range of security levels — from a simple mobile wallet to a high-security vault. As time goes on, the use of private keys will become more widespread. We envision a future where private keys will secure everything important to us: money, identity, communications, and personal data. We are excited to continue our journey toward a world where people can take back control of their money, savings, and digital lives, and we appreciate all of the Casa members, teammates, and supporters who continue to make our work possible.

Consumer Products
Hardware
Security
11 - 50 employees
Seed

CAT Labs is a cybersecurity startup focused on developing digital asset recovery and investigative tools to combat tech-enabled crime. Their key products, Recovery CAT and Security CAT, are designed to assist government agencies and private sector clients in identifying, seizing, and protecting digital assets, particularly cryptocurrencies. With a team of former DOJ and Department of Defense experts, CAT Labs aims to address the challenges posed by global crime syndicates and cybercriminals. The company is positioned in the rapidly growing cybersecurity forensics market, which is projected to reach over $30 billion, and has already raised $4.3 million in pre-seed funding to further its mission.