Firefish, the open marketplace for bitcoin-collateralized loans, announced the successful close of a $1.8 million seed funding round, marking a major milestone in its mission to make secure, trust-minimized Bitcoin-backed loans accessible worldwide. The company now offers instant USDC loans to users in the U.S. and across global markets, expanding access to stablecoin-based liquidity for Bitcoin holders.
The round was backed by a select group of investors, including Braiins, the world’s oldest Bitcoin mining pool and creators of the open-source mining software Braiins OS, and Miton, a Prague-based venture capital firm focused on startups across Europe. With EUR already supported, Firefish now also offers the option of CHF loans and USDC instant loans to users in the U.S., Switzerland, and the rest of the world, where borrowers can secure liquidity in as little as 15 minutes.
“We’re not reinventing TradFi with Bitcoin on the surface—we’re rebuilding lending from the ground up using Bitcoin’s core principles,” said Martin Matejka, Firefish CEO and Co-Founder. “This investment validates our vision and demonstrates that Bitcoin-native lending can be done at scale—without taking shortcuts. Firefish is where serious capital meets Bitcoin-native infrastructure, with open price discovery and zero rehypothecation.”
With over $100 million in transaction volume, 10,000+ users, and nearly 1,000 BTC in escrowed collateral, Firefish is rapidly establishing itself as a major force in Bitcoin-native finance. In March 2025, Firefish recorded triple-digit month-over-month growth, driven by thousands of Bitcoiners looking for loans and yield-seeking lenders attracted to its market-driven rates, compelling risk-reward profile, and a borrower-driven model that lets lenders pick the best deal.
Unlike the centralized crypto lenders that have historically operated in the industry, Firefish does not hold user assets, which are never rehypothecated. Bitcoin collateral is locked in on-chain escrow using multi-signature contracts, and fiat loans are settled directly between borrowers and lenders via standard bank transfers or stablecoins. Firefish’s advanced recovery feature allows for the Bitcoin collateral to still be recoverable in case of disastrous scenarios by using a pre-signed recovery transaction.
With Firefish, institutional investors and high-net-worth individuals can deploy capital in bulk using fiat or stablecoins and be matched with qualified borrowers. These investments will soon be able to take place through traditional fund structures, which could enable even broader participation.
Braiins recently used Firefish to secure a $400,000 loan, leveraging their Bitcoin to expand the company’s operations without having to sell. “It took less than 24 hours to collateralize 8.75 BTC and borrow euros,” said Eli Nagar, CEO of Braiins. “This investment reflects our belief that Bitcoin holders don’t want counterparty risk. With Firefish, the rules are enforced by code, not third-party trust.” Braiins is also offering Bitcoin miners the option of purchasing their hardware using Bitcoin-backed loans powered by Firefish and is integrating it into its product suite.
Last year, Braiins and Firefish co-published “Bitcoin: The Ultimate Collateral”, a book that analyzes how lending is the natural next step for Bitcoin and how Bitcoiners can use it to their advantage. As outlined in the book, traditional finance companies can now earn yield in the Bitcoin credit market—all without having to touch Bitcoin or manage any infrastructure.
Besides accelerating its global expansion, the funding will be used to further scale Firefish Prime institutional lending program. Firefish joins Prague’s long-standing Bitcoin tradition alongside pioneering companies like SatoshiLabs, Braiins, General Bytes, Confirmo and Coinmate—cementing the city and the country’s status as a global hub of Bitcoin innovation.
About Firefish
Firefish is the open marketplace for bitcoin-collateralized loans. Drawing on decades of experience in banking and capital markets, Martin Matejka and Igor Neumann founded Firefish to offer Bitcoin holders a simple and secure way to borrow cash against their Bitcoin without relying on a custodian. Using on-chain escrow and peer-to-peer matching, Firefish allows users to use their Bitcoin without having to sell and trigger capital gains taxes. Learn more at firefish.io
About Braiins
Braiins is a pioneer in bitcoin mining software and hardware, including the widely renowned Braiins OS. Headquartered in Prague, Braiins is committed to making bitcoin mining more accessible, efficient, and profitable for miners worldwide. For additional information, visit braiins.com.