Firefish is an open lending marketplace that facilitates Bitcoin-backed loans, connecting borrowers and investors directly without intermediaries. Borrowers can secure fiat or stablecoin loans by collateralizing their Bitcoin holdings, allowing them to access liquidity without selling their assets. Investors provide funds for these loans and earn fixed interest rates, with the security of Bitcoin collateral exceeding the loan value. The platform operates on a peer-to-peer basis, ensuring transparency and security through an on-chain escrow system.