DeFi — Decentralised Finance — is the attempt to rebuild financial services (lending, borrowing, trading, insurance) using smart contracts on public blockchains, without banks, brokers, or any centralised intermediaries. Here is how it works, what it has achieved, and why it keeps blowing up.
Educational content only — not personalized financial, legal, or tax advice.
Decentralised Finance (DeFi) represents a structural shift in financial infrastructure, replacing traditional intermediaries like commercial banks, brokerages, and clearinghouses with automated, self-executing software protocols deployed on public blockchains. As of 2026, global Total Value Locked (TVL) across DeFi protocols exceeds $100 billion, with Ethereum, Arbitrum, Solana, and Binance Smart Chain functioning as primary settlement layers.
Whereas traditional banking relies on institutional balance sheets and regulatory oversight to process transactions, DeFi executes financial transactions using smart contracts—immutable code deployed on-chain.
Decentralised exchanges (DEXs) such as Uniswap and Curve bypass traditional order books. Instead, trading relies on liquidity pools governed by mathematical formulas, most notably the constant-product market maker model:
$$x \times y = k$$
Where $x$ and $y$ represent the pool quantities of two tokens, and $k$ is a constant invariant. Traders swap tokens directly against the pool, paying a protocol fee (typically 0.05% to 0.30%) distributed to liquidity providers (LPs).
DeFi lending platforms like Aave and Compound operate permissionless money markets. Borrowers secure loans by depositing crypto collateral at strict Loan-to-Value (LTV) limits:
| Metric / Parameter | Traditional Commercial Bank | DeFi Protocol (e.g., Aave v3) | |---|---|---| | Identity / Approval | KYC/AML, credit score check | Permissionless (wallet signature) | | Collateral Requirement | Unsecured or 100% property value | Over-collateralized (125% - 150% LTV) | | Interest Rate Discovery | Central bank rates + credit margin | Dynamic algorithmic utilization curves | | Liquidation Execution | Court process / foreclosure (months) | Automated bot liquidations (seconds) | | Settlement Time | T+1 to T+3 business days | Real-time block confirmation (~12 secs) |
If market price declines push a borrower's collateral ratio below the liquidation threshold (e.g., 82.5%), automated liquidator bots trigger smart contract liquidations, selling collateral at a 5% to 10% discount to maintain protocol solvency.
Yield farming incentives encourage users to supply capital to emerging protocols. In addition to base interest paid by borrowers, liquidity providers receive protocol governance tokens (e.g., UNI, AAVE). These tokens grant voting rights over protocol fees, collateral parameters, and treasury disbursements.
However, yield farmers face impermanent loss—the opportunity cost incurred when token price ratios diverge significantly while locked in an AMM pool compared to simply holding the assets in a wallet.