Bitcoin Holders
Are Using This (Not Selling)

About Igor Neumann

Igor Neumann is co-founder and COO of Firefish, with a career built in financial markets before Bitcoin. He spent years in prop trading (starting during the dot-com bust) and then nearly two decades at Thomson Reuters and the London Stock Exchange Group providing financial data and infrastructure to banks and trading firms. He ran a Bitcoin full node as early as 2015, and a stint living in Russia during the outbreak of the war with Ukraine, when his local bank account became unusable as a foreigner, is what turned him from trader into self-sovereignty convert.

Firefish is a Prague-based, non-custodial marketplace for Bitcoin-backed loans, not a lender itself. Instead of sitting between borrower and an opaque balance sheet like the 2022-era BlockFi/Celsius generation, it matches individual borrowers and lenders and locks the BTC collateral directly on-chain in a 3-of-3 multisig escrow with pre-signed transactions. Rehypothecation is structurally impossible, and a pre-signed time-locked 'zombie apocalypse' recovery transaction returns the Bitcoin to the borrower one month after maturity even if Firefish disappears entirely. The codebase is open source, the platform is EU-regulated (MiCA), and roughly 150M USD of notional has been processed with zero price liquidations to date.

This conversation is worth watching because Igor walks through the actual mechanics rather than the pitch: how the 3-of-3 multisig is constructed, why an ephemeral key is used, what the four possible transaction paths are, exactly when margin calls fire, what happens at 95 percent LTV, and why borrowers should never pledge their full stack. It is one of the clearer, un-sanitized explanations of how a post-Celsius BTC loan product is supposed to work.

What was said

1. 25:00 Firefish is a non-custodial peer-to-peer marketplace: the borrower sets their own terms (amount, tenor, rate) and waits to be matched, rather than accepting a bank's take-it-or-leave-it offer.
2. 28:00 Collateral is locked in a 3-of-3 multisig escrow with four pre-signed paths: return to borrower on repayment, send to liquidator on default, send to liquidator on price liquidation, or a time-locked 'zombie apocalypse' recovery transaction that returns BTC to the borrower one month after maturity if Firefish ever disappears.
3. 31:00 The borrower signs only once at setup with an ephemeral key that is then destroyed, and Firefish holds two of the three keys solely to arbitrate repayment vs default; the lender holds no key so that non-Bitcoin-native capital (Igor's example: his retired mother) can participate without any on-chain interaction.
4. 40:00 Default LTV is 50 percent (borrow 10k, lock 20k of BTC), but average LTV on the platform sits around 40-45 percent because Bitcoiners voluntarily over-collateralize to avoid liquidation; in the recent drawdown over 1,000 users topped up collateral to stay safe.
5. 45:00 Liquidation is binary at 95 percent LTV, not partial: there is a 5 percent premium reserved for the liquidator, and Igor's rule of thumb is to never lock your entire stack so you always have dry powder to top up.
6. 48:00 Firefish revenue model is a flat 1.5 percent per annum origination fee from the borrower; across roughly 150M USD in loans and ~3,300 BTC of collateral processed, they have had zero price liquidations and only a handful of defaults.
7. 50:00 Loans are bullet-style (one payment at maturity, no monthly amortization) with tenors from 3 months to 2 years; euro rates currently run ~6-7 percent for 3-month and ~12-13 percent for 2-year, and the Czech koruna book has compressed almost to the central bank rate because of heavy domestic lender liquidity.
8. 68:00 Biggest user mistake Igor has seen: a borrower set an exchange-controlled address as their BTC return address, the exchange went bust mid-loan, and the BTC would have been lost on repayment, so the return address must always be self-custodied.