What Is DeFi? How Decentralized Finance Works (2026)

Decentralized finance, or DeFi, lets you lend, borrow, trade, and earn interest on crypto directly from your own wallet, with no bank, broker, or account application in between. Instead of a company holding your funds and approving your transactions, software on a blockchain does the job. This guide explains what DeFi actually is, how it works under the hood, what it costs you in risk, and how it gets taxed.

What Is DeFi (Decentralized Finance)?

DeFi (decentralized finance) is a category of financial applications built on public blockchains that let you trade, lend, borrow, and earn interest on crypto without going through a bank, broker, or other traditional intermediary. You connect a wallet directly to a protocol, and the protocol's code, not a company's back office, executes the transaction.

The term covers a wide range of services. A decentralized exchange lets you swap one token for another. A lending protocol lets you deposit crypto to earn interest or borrow against it as collateral. A staking protocol lets you lock up tokens to help secure a network and earn a reward for it. What ties all of these together is that no single company custodies your funds or approves your transaction: the rules live in open, publicly viewable code.

DeFi vs. Traditional Finance

Traditional finance runs through institutions. A bank holds your deposit, verifies your identity, and decides whether to approve your loan. Those institutions provide real services, including deposit insurance and a support line, but they also add friction, fees, and operating hours.

DeFi removes the institution from the middle of the transaction. A smart contract enforces the rules instead of a loan officer, and the ledger recording the transaction is public rather than held in a private database. That trade-off cuts both ways: you get more direct control and around-the-clock access, but you also give up the safety nets that come with a regulated institution.

How Does DeFi Work?

DeFi combines three layers that work together: a blockchain to record transactions, smart contracts to enforce the rules, and applications that give you a way to interact with both.

Blockchain Technology

At the base sits the blockchain, a distributed ledger that records every transaction across a network of independent computers rather than in one company's database. Because the ledger is public and replicated across the network, no single party can quietly alter a past transaction, and anyone can independently verify the current state of the system.

Smart Contracts

On top of the blockchain sit smart contracts: self-executing programs with the terms of an agreement written directly into code. When the conditions in the contract are met, such as a borrower posting enough collateral, the contract executes automatically, with no human approval step in between. Most DeFi activity, including nearly all of it discussed in this guide, runs on Ethereum, the blockchain where smart contracts became a mainstream building block.

Decentralized Applications (dApps)

The layer you actually interact with is the dApp: a website or app that gives you a front-end interface to a set of smart contracts. When you connect your wallet to a dApp and click "swap" or "deposit," you are authorizing a transaction that a smart contract will carry out. The dApp itself does not hold your funds at any point.

How Big Is DeFi?

DeFi's size is usually measured in total value locked (TVL), the combined value of crypto deposited across lending, trading, and staking protocols. TVL swings heavily with crypto prices and market sentiment, so it is a snapshot, not a stable number.

As of June 2026, total DeFi TVL stood at about $70 billion, down from roughly $115 billion in January of the same year, according to market reporting based on DefiLlama tracking data. Ethereum alone accounted for roughly 53% of that total, reflecting how concentrated DeFi activity still is on the blockchain where it originated. The drop through the year illustrates a pattern worth remembering: DeFi's scale moves with the broader crypto market, and a TVL figure from even a few months ago can already be out of date.

Key DeFi Applications & Examples

DeFi is not one product. It is a set of distinct use cases, each with its own protocols and its own risk profile.

Decentralized Exchanges (DEXs)

A decentralized exchange lets you swap one token for another directly from your wallet, without a company like a centralized exchange taking custody of your funds first. Uniswap popularized the automated market maker model, where a smart contract prices trades against a pool of two tokens instead of matching individual buy and sell orders on an order book.

Curve uses a similar pooled-liquidity model tuned specifically for trading between assets of similar value, such as different stablecoins, which keeps slippage low. The same model runs on other chains under different names, including PancakeSwap on BNB Chain and SushiSwap, a Uniswap fork with its own governance token. Our guide to the best decentralized exchanges compares the leading options in more depth, and if Uniswap is part of your activity, our Uniswap taxes guide covers the reporting side.

Lending & Borrowing

Aave and Compound are the two protocols most associated with DeFi lending. Both let one group of users deposit crypto into a shared pool to earn interest, while another group borrows from that pool by posting more collateral than they borrow.

Stablecoins

Stablecoins are digital assets designed to hold a steady value, usually pegged to the US dollar, which makes them useful as a stable unit of account inside an otherwise volatile market. Sky, formerly known as MakerDAO, issues two stablecoins: DAI and its newer successor USDS. Both are backed by crypto collateral and real-world assets locked in smart contracts, with no company holding reserves in a bank account. That makes Sky one of the few stablecoin issuers that is itself a DeFi protocol.

Staking

Staking means locking up crypto to help secure a network or a protocol, in exchange for a reward. In a DeFi context, staking often overlaps with lending: you deposit an asset into a protocol, the protocol puts it to work, and you earn a yield for the time it sits there.

Yield Farming & Liquidity Pools

Yield farming means actively moving crypto between different protocols and liquidity pools to chase the highest available return. It usually starts with becoming a liquidity provider: depositing a pair of tokens into a pool like the ones Curve or Uniswap run, and earning a cut of the trading fees generated by swaps against that pool. Returns can look attractive, but they carry a specific risk called impermanent loss, where the value of your deposited pair can end up lower than if you had simply held the two tokens separately.

Benefits of DeFi

DeFi's advantages come directly from removing the intermediary, and they are real, even if they come with trade-offs covered in the next section.

• Open access: anyone with an internet connection and a wallet can use most DeFi protocols, with no application or approval process.
• Around-the-clock availability: protocols run continuously, with no business hours, weekends, or bank holidays.
• Transparency: transactions and the code governing a protocol are publicly viewable on the blockchain, so activity can be independently verified.
• Lower structural costs: without a company's overhead built into the fee, many DeFi transactions cost less than the equivalent traditional-finance service.
• Composability: because protocols share the same underlying blockchain and open standards, they can be combined. A token borrowed on one protocol can be deposited into another in the same transaction: borrowing a stablecoin from a lending protocol and depositing it into a yield pool in a single step is a typical example.

Risks & Disadvantages of DeFi

DeFi's benefits are matched by real risks, and understanding them matters more than any single benefit on the list above.

Smart Contract & Technical Risk

A peer-reviewed risk analysis of DeFi weighted technical risk, including smart contract vulnerabilities, at nearly 32% of total DeFi risk, ahead of legal and regulatory risk at roughly 26% and financial risk at roughly 24%. A bug in a smart contract, once exploited, cannot simply be patched the way a traditional bank could reverse a fraudulent transaction: on most blockchains, the transaction is final.

Centralization Behind the Curtain

DeFi markets itself as decentralized, but research from the Bank for International Settlements has found that DeFi often carries substantial de facto centralization, whether through dApp front-ends acting as centralization vectors, opaque or undisclosed developer identity and control, or ambiguous DAO governance. That same research points to information asymmetries and market inefficiencies as structural risks DeFi has not eliminated, despite early marketing suggesting otherwise.

Regulatory Uncertainty

Regulation is still catching up to DeFi. The UK's Financial Conduct Authority has said its rules apply to DeFi firms only where an identifiable controlling entity exists, leaving genuinely decentralized protocols in a gray area, while stating plainly that cryptoassets remain high risk under its regime. In the US, the Securities and Exchange Commission (SEC) and Commodity Futures Trading Commission (CFTC) signed a coordination Memorandum of Understanding in March 2026 and jointly published a shared token-classification taxonomy, but both agencies still evaluate individual DeFi projects on a case-by-case, fact-specific basis rather than under one DeFi-specific framework.

Market Volatility & No Safety Net

Crypto prices can move sharply within hours, and DeFi has no deposit insurance and no customer support line to call if a protocol is exploited or a token collapses in value. If you lose access to your wallet or send funds to the wrong address, there is generally no institution that can reverse it.

How to Get Started With DeFi

Getting started is more about preparation than technical skill. The steps below are the same regardless of which protocol you end up using.

1. Set up a wallet. A self-custody wallet such as MetaMask, Trust Wallet, or Coinbase Wallet stores your private keys and connects to DeFi protocols. Back up your seed phrase offline and never share it.
2. Fund the wallet. Transfer crypto in, typically ETH for gas fees plus whatever asset you plan to use, such as a stablecoin.
3. Choose a protocol that matches your goal. A decentralized exchange for trading, a lending protocol for earning interest, or a staking protocol for network rewards.
4. Connect your wallet and start small. Confirm the transaction details before signing, and test with a small amount before committing more.

Is DeFi Regulated? DeFi Laws in the US and UK

DeFi sits in a legal gray area in most jurisdictions, largely because it was built to route around the intermediaries that existing financial law was written to regulate. Regulators are responding by applying existing rules where they clearly fit and building new guidance where they do not.

DeFi Regulation in the US

In the United States, DeFi activity can fall under securities law, commodities law, or anti-money-laundering rules depending on how a specific protocol is structured. The SEC evaluates whether a project's token functions as a security, and the CFTC asserts jurisdiction over crypto assets that function as commodities. Since March 2026, the two agencies have coordinated under a joint MOU and a shared five-category token taxonomy, but neither treats "DeFi" itself as a single, uniformly regulated category, and evaluation of individual projects remains fact-specific.

DeFi Regulation in the UK and EU

In the United Kingdom, the Financial Conduct Authority (FCA) takes a similar case-by-case approach. Its published guidance states that FCA rules apply to a DeFi arrangement only when there is an identifiable controlling entity behind it, and that genuinely decentralized activity may fall outside the regulatory perimeter entirely, at least for now. The European Union has taken a more codified route with MiCA, a single licensing framework that applies the same rules to crypto-asset service providers across member states, though it runs into the same open question as the FCA's approach when a protocol has no controlling entity to license in the first place.

How Is DeFi Taxed?

Most tax authorities do not treat "DeFi" as its own special category, though some, including the UK's HMRC, have published DeFi-specific guidance covering lending and staking. Outside those exceptions, the same principles that apply to other crypto transactions apply here: a taxable event is usually triggered by a disposal, such as selling, swapping, or spending a token, or by receiving new tokens as income, such as staking rewards, crypto interest from lending, or yield farming payouts.

How the US Taxes DeFi

In the US, swapping tokens on a decentralized exchange, closing out a lending position, or claiming a farming reward can each trigger a reportable event, whether as a capital gain or as ordinary income depending on the transaction type. Staking rewards are treated as ordinary income at the moment you receive them, separate from any later gain or loss when you sell the asset.

How the UK Taxes DeFi

HMRC applies a comparable framework. The UK Autumn Budget 2025 proposed 'no gain, no loss' treatment for certain DeFi lending, staking, and AMM transactions, covering deposits, withdrawals, and borrowing or collateral moves, though not the rewards themselves, which stay taxable as income; this change is not yet law, so current HMRC guidance still applies. Our UK crypto lending tax guide and UK crypto staking tax guide cover the current rules in detail. Because tax treatment varies by country and by the exact mechanics of a protocol, always confirm the current rules for your jurisdiction rather than assuming your DeFi activity is treated the same everywhere.

The practical difficulty with DeFi taxes is rarely the tax rule itself. It is reconstructing dozens of small transactions across multiple wallets and protocols after the fact, which is exactly the gap crypto tax software is built to close. CoinTracking imports transactions directly from wallets and supports DeFi activity across a wide range of protocols, so lending interest, swaps, and staking rewards land in your tax report instead of a manual spreadsheet.

Conclusion

DeFi replaces the bank in the middle of a financial transaction with a smart contract, and that trade brings real advantages, including open access and around-the-clock availability, alongside real risk, including smart contract failure and the absence of a safety net. Understanding both sides, rather than just the upside, is what separates a considered DeFi user from someone who found out the hard way. If you are already active in DeFi, CoinTracking can handle the transaction tracking and tax reporting once you get started.