Not financial, legal, or tax advice. This guide is for general education only. DeFi is experimental and carries significant risks, including total loss of funds. Do your own research and proceed with caution.

DeFi, short for decentralized finance, is a set of financial services that run on public blockchains instead of through banks or brokers. Using smart contracts, DeFi lets people lend, borrow, trade, and earn yield directly with one another, with software rather than institutions handling the transactions.

Table of Contents

What DeFi is

Traditional finance runs through intermediaries. A bank holds your deposits and decides who can borrow. An exchange matches buyers and sellers. DeFi aims to provide those same functions without the intermediary, using programs on a blockchain that anyone can access.

The building block is the smart contract, a self-executing program covered in What Is Ethereum. Because these contracts run automatically and are open for anyone to inspect and use, DeFi services tend to be permissionless (open to anyone with a wallet), transparent (activity is visible on-chain), and composable (applications can plug into one another). Most DeFi activity has historically taken place on Ethereum, though other networks host thriving ecosystems too.

How DeFi works

At the center of DeFi are smart contracts that hold funds and enforce rules. Instead of signing paperwork with a company, you interact directly with a contract from your own wallet (see What Is a Crypto Wallet). You connect your wallet to an application, approve a transaction, and the contract does the rest, whether that is swapping one token for another, supplying funds to a lending pool, or something more complex.

Because everything is code, the terms are explicit and execute exactly as written. That transparency is a genuine strength, and it comes with a matching weakness: if the code has a flaw, there is no manager to appeal to, and losses can be immediate and permanent.

Staking and earning yield

One of the most common reasons people explore DeFi is to earn a return on assets they already hold.

Staking in the broad sense means committing crypto to help support a network or protocol in exchange for rewards. On proof-of-stake networks, this can mean helping secure the blockchain itself. In DeFi apps, related mechanisms let you supply assets and earn yield. For a focused explanation, see What Is Staking.

It is important to understand that advertised yields are not guaranteed and often reflect real risk. High returns can come from token incentives that may not last, or from strategies that can lose money quickly if conditions change.

Lending and borrowing

DeFi lending platforms let users supply assets to a pool and earn interest, while borrowers take loans from that pool by posting collateral. There is no credit check. Instead, loans are typically over-collateralized, meaning you must lock up more value than you borrow. If the value of your collateral falls below a threshold, the protocol can automatically sell it to repay the loan, a process called liquidation. This design lets strangers lend to one another safely through code, though it exposes borrowers to the risk of losing collateral during sharp price moves.

Decentralized exchanges

A decentralized exchange, or DEX, lets you trade one token for another directly from your wallet, without handing custody to a company. Many DEXs use liquidity pools, where users deposit pairs of tokens that others can trade against, and those depositors earn a share of the trading fees. DEXs are a core piece of DeFi because they let value move freely between the many tokens covered in What Are Crypto Tokens, all without a central operator.

Risks to understand

  • Smart contract risk. Bugs and exploits can drain funds instantly, and DeFi has seen many large hacks.
  • Volatility and liquidation. Collateralized positions can be liquidated quickly during sharp price swings.
  • Scams and rug pulls. Some projects are designed to steal deposits. Anonymous teams and unaudited code are red flags.
  • Complexity. DeFi assumes a fair amount of knowledge, and mistakes are easy to make and hard to reverse.
  • Regulatory uncertainty. The legal status of many DeFi activities is still developing.

Because of these risks, many experienced users treat DeFi as an advanced area and commit only what they can afford to lose. See How to Keep Your Crypto Safe.

How to get started

Build a solid base first (What Is Cryptocurrency, What Is Ethereum, What Is a Crypto Wallet), since DeFi assumes comfort with all three. If you choose to explore, start with well-established, widely audited applications, use small amounts while you learn, and be skeptical of unusually high advertised returns. Understanding a protocol before you deposit is the single best protection you have.

Learn the fundamentals before you explore with Hodl Up. DeFi rewards people who understand what they are doing. Hodl Up helps you build a strong foundation with the core assets first, so that if you later venture into decentralized finance, you do it from a place of knowledge rather than hype.