Bitcoin-backed loans. Finally done right.


Firefish for investors

Use the power of Bitcoin. Secure your investment.

Investors often face a dilemma when it comes to balancing risk and return. On Firefish, each loan is secured by bitcoin collateral so the risk of not being paid back is completely removed.

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Repayment guaranteed

The value of the locked bitcoin is always higher than the loan, so there is no risk of losing your investment.

No bitcoin handling required

Although loans are secured by bitcoin, investors don't need to interact with bitcoin or hold any private keys.


The Firefish protocol and much of its implementation code are open source. Each escrow is visible on the bitcoin blockchain, allowing for easy verification.

Minimal trust required

Bitcoin is securely locked in a smart contract built on top of the bitcoin network, and Firefish has limited control over the collateral.


Loans are made directly between members of the platform.

Suitable for institutions

Firefish loans offer zero credit risk and attractive yields, with no need for institutional investors to interact with the blockchain.

Advanced technology

Firefish uses cutting-edge technology to facilitate secure, transparent loans.

How it works

Invest Your

Use our platform to invest your cash liquidity in loans secured by bitcoin collateral.


Earn an attractive, inflation-beating interest. Risks removed.

Redeem Your

Receive your investment and accrued interest back, automatically. Reinvest

Our strengths

Boost your investment earnings with the power of bitcoin.

Firefish uses bitcoin collateral to secure your investment and deliver higher returns without increasing risk.

Say goodbye to the risk-return trade-off.


Current interest rates

  • USD
    5% p.a.
  • EUR
    6% p.a.
  • CZK
    7% p.a.


Juraj Bednár“Bitcoiners need a way to make use of their investment without doing the worst thing - selling their Bitcoin. Firefish is a great Bitcoin-native way to use Bitcoin as a collateral without selling it, built by Bitcoiners.”

Juraj Bednár

enterpreneur, educator

Ondřej Raška“Firefish is an exceptional team. They have built a service that does it right compared to centralized solutions.”

Ondřej Raška

Founding partner at Miton

Kixunil“After thorough analysis I concluded that the design is very secure, paranoid even. All hard core Bitcoiners should really enjoy it!.”


Bitcoiner. Rust-bitcoin contributor


loans essential knowledge.

  • To ensure the security of your loan, we require the borrower to place their bitcoin in a designated multi-signature escrow address. You can easily track the activity of this escrow address using a public blockchain explorer.
  • Your investment is always protected, as the value of the collateral exceeds the value of the loan.
  • If the value of the bitcoin collateral drops close to the value of the loan (for example, due to a decline in the bitcoin exchange rate), the collateral will be sold on the open market and the proceeds used to pay back your investment. This process is called liquidation. Liquidation may also occur if the borrower fails to pay back the loan on the due date.
  • You don't need to worry about handling, trading, or exchanging bitcoin yourself. You can choose to use a trusted third party, known as the liquidator, to handle the process of liquidation on your behalf. However, if you are comfortable working with bitcoin, you have the option to opt-out and act as your own liquidator.