What Is DeFi? Decentralized Finance Explained
Risk notice: This article is for general information only and is not financial or investment advice. Crypto-assets and DeFi protocols are highly volatile and risky, and you can lose all of the money you put in. Do your own research and consider consulting a licensed advisor before investing.
Decentralized finance, usually shortened to DeFi, is one of the most talked-about areas of the crypto world. But what exactly is DeFi, how does it work, and what risks should you understand before you touch it? This guide explains the basics in plain language.
What is DeFi?
Decentralized finance provides financial instruments and services through smart contracts on a programmable, permissionless blockchain. The idea is to reduce the need for intermediaries such as brokerages, exchanges or banks. On DeFi platforms, users can lend or borrow funds, speculate on price movements with derivatives, trade cryptocurrencies, insure against risks and earn interest in savings-like accounts.
A core principle of DeFi is accessibility. Because the applications – commonly called “dApps” – run on public blockchains, users around the world can access financial services without a centralized authority. Developers can also combine different protocols like building blocks to create new products, a concept often called “money Legos”.
A short history of DeFi
The Ethereum blockchain popularized smart contracts, the basis of DeFi, in 2017. MakerDAO, established in 2017, became a prominent lending platform built around DAI, a stablecoin pegged to the US dollar. In September 2024 MakerDAO rebranded as Sky, and DAI was renamed USDS.
In June 2020 the lending protocol Compound began rewarding lenders and borrowers with its own token, Comp. Other platforms followed, giving rise to “yield farming” or “liquidity mining”, in which speculators move crypto-assets between pools and platforms to maximize total yield. By 2021, protocols such as MakerDAO, Compound, Aave and Uniswap had driven total value locked (TVL) to over $180 billion. The 2022 market crash, following the collapse of Terra/LUNA and FTX, exposed serious vulnerabilities and triggered a downturn, before DeFi began recovering in 2023 with trends such as the tokenization of real-world assets and Layer 2 networks like Arbitrum and Optimism.
How DeFi works
In DeFi, transactions are made directly between participants and mediated by smart contract programs rather than a central intermediary. These protocols typically run on open-source software. Users usually access dApps through a browser extension or app – for example, MetaMask lets users interact with Ethereum through a digital wallet.
- Lending protocols: stablecoin holders lend assets to a liquidity pool, and others borrow them by depositing their own collateral. Interest rates adjust automatically based on demand.
- Decentralized exchanges (DEXs): Uniswap, for instance, lets users trade Ethereum tokens without a central order book. Users who supply liquidity pools receive a share of trading fees.
- Flash loans: popularized by Aave, these are uncollateralized loans taken out and repaid within a single blockchain transaction.
- Oracles: some dApps pull external data, such as asset prices, into the blockchain through oracles.
The risks of DeFi
Some DeFi applications advertise high interest rates, but they carry high risks:
- Bugs and hacks: coding errors and hacks are common. Blockchain transactions are irreversible, so an incorrect or fraudulent transaction may never be corrected.
- Lost keys: with no KYC process and no way to revert a transaction, users who lose passwords or private keys to a hacker have no recourse.
- Impermanent loss: liquidity providers can lose value when the relative price of the deposited token pair shifts before withdrawal.
- Price impact, slippage and front running: large trades move prices in a pool, and other participants may place their transactions ahead of yours.
- Rug pulls and fraud: the people behind a protocol may be unknown and may disappear with investors’ money. Inexperienced investors are especially at risk, because there is no intermediary offering customer support.
DEXs are particularly exposed to cyberattacks: in 2025 at least 20 incidents were reported, with aggregate losses of $535 million.
How decentralized is DeFi really?
Protocols vary widely. If smart contracts are fixed and contain no access-restricted functions, a protocol may act as neutral infrastructure. If contracts are upgradeable or key functions are restricted to certain users, that neutrality can be compromised. Governance tokens grant voting rights, but they are often concentrated among a few holders and rarely used to vote.
Regulation
In October 2021 the FATF included DeFi in its guidance for crypto service providers, leaving each country to decide whether participants count as virtual asset providers. In the EU, the MiCA regulation came into effect in 2024, affecting stablecoin issuers and custodial services.
