DeFi
DeFi, or Decentralized Finance, refers to a broad ecosystem of financial applications built on blockchain networks that replicate traditional financial services — lending, borrowing, trading, and earning yield — without centralized intermediaries.
Traditional finance relies on banks, brokerages, and clearinghouses to hold assets, facilitate transactions, and enforce contracts. DeFi replaces these centralized intermediaries with smart contracts — self-executing code deployed on a blockchain — that automatically enforce the terms of financial agreements without any single party controlling the outcome. The Ethereum blockchain hosts the largest share of DeFi activity, though other chains including Solana, Avalanche, and BNB Chain have grown significant DeFi ecosystems of their own.
The most widely used DeFi applications fall into several categories. Decentralized exchanges (DEXs) such as Uniswap use automated market maker (AMM) algorithms to allow users to swap tokens directly from their own wallets without a central order book. Lending protocols such as Aave and Compound allow users to deposit crypto assets as collateral and borrow against them, with interest rates set algorithmically based on supply and demand. Yield aggregators automatically move funds across protocols to maximize the interest rate earned.
Liquidity providers — users who deposit token pairs into DEX pools — earn trading fees in exchange for providing the liquidity that makes the exchange function. This is often presented as a yield-generating strategy, though it carries a risk called impermanent loss: if the relative prices of the two tokens in the pool diverge significantly, the provider may end up with less total value than if they had simply held the tokens individually.
DeFi grew explosively from 2020 through 2021, with total value locked (TVL) across all protocols peaking at over $250 billion. However, the ecosystem has also suffered numerous high-profile hacks, exploits, and smart contract vulnerabilities, resulting in billions of dollars of user losses. Smart contract audits, formal verification, and insurance protocols have emerged to address these risks, but they remain significant.
Regulatory treatment of DeFi in the United States is still evolving. The SEC, CFTC, and FinCEN have each asserted jurisdiction over different aspects of DeFi activity, and the legal status of governance tokens, yield-bearing products, and DEX operators remains actively debated.