Compound Explained: Ethereum DeFi Lending Guide for 2026

Compound is a decentralized lending protocol that runs on smart contracts. Users supply crypto to pools and earn interest, or deposit collateral and borrow other assets against it. There is no bank or loan officer. Rates are set by the protocol according to supply and demand within each market.

The protocol is governed by holders of its COMP token, who vote on changes such as which assets are listed, collateral factors and reserve settings. Because Compound has operated on Ethereum since 2018 and has been studied extensively, it is often used as a reference point when people compare other lending markets.

Compound is a useful case study because it shows the core building blocks of DeFi lending in one place: pooled liquidity, algorithmic interest rates, overcollateralized loans, and on-chain governance.

• Suppliers deposit an asset and receive a claim that grows in value as interest accrues.
• Borrowers lock collateral and draw loans up to a limit set by collateral factors.
• Liquidators can repay part of an unhealthy loan and receive collateral at a discount.
• COMP holders vote on protocol parameters.

For current listed assets, deployed versions and supported networks, check the protocol's official documentation, because markets are added and retired over time.

Compound uses liquidity pools rather than matching individual lenders with individual borrowers. Everyone who supplies an asset adds to a shared pool for that market. Borrowers draw from the same pool.

When many people want to borrow an asset, its borrow rate rises, and the supply rate paid to lenders generally rises with it. When demand is low, rates fall. The rate is a function of utilization, meaning the share of supplied funds currently borrowed.

Some points to understand:

• Rates can change at any time and are not guaranteed.
• Lenders do not choose a term or a fixed return.
• Interest accrues continuously, so balances grow over time.
• Withdrawal may be limited if most of a pool is already borrowed.

This design means the yield you see is a snapshot. Treat it as a variable figure and review it regularly.

To borrow on Compound, you first supply collateral. Each asset has a collateral factor that determines how much you can borrow against it. For example, a protocol might allow borrowing up to a set percentage of the collateral's value. The exact percentages are set by governance and can change.

A position is healthy while the value of your collateral, adjusted by its factor, stays above the value of your debt. If the collateral price falls or the debt grows, the position can become undercollateralized. At that point, a liquidator may repay part of the loan and buy your collateral at a discount, which is a cost to the borrower.

A simple way to think about borrowing:

1. Decide the purpose of the loan and how long you need it.
2. Borrow well below your maximum limit to leave room for price moves.
3. Monitor the health factor or equivalent figure on the interface.
4. Repay or add collateral before the position approaches liquidation.

Borrowing against volatile assets carries real liquidation risk, even when the protocol itself works as designed.

Compound has released several versions over time. Compound V2 used a model where each market was a separate pool with its own cToken. Compound V3, often called Comet, simplified the design around a single base asset per market, such as USDC on some deployments, which borrowers repay and suppliers earn on.

Compound V3 is live on Ethereum and several other networks. Because deployments and markets vary, check the official site for which versions and chains are active before you use one. Older versions may still hold funds, and governance decisions can change which markets remain available.

If you read a guide or forum post, make sure it refers to the version you plan to use. Mechanics such as collateral rules and rate models differ between versions.

Compound is governed by COMP token holders. Proposals, such as adding a new asset, changing collateral factors or adjusting reserve settings, are submitted and voted on by the community. Approved changes are executed through the protocol's governance process.

For people using the protocol, this means the rules are not fixed. A market you use today could receive new parameters tomorrow. Following governance announcements through official channels helps you notice changes that affect your positions.

Governance also shapes risk. Decisions about which collateral to accept and how much it can support determine how exposed the protocol is to sudden price moves. Reading proposals, even briefly, gives insight into how a lending protocol manages its own risk.

Compound is one of several lending protocols on Ethereum. Each makes different trade-offs between simplicity, asset coverage, risk controls and yield.

• Aave V3 is a non-custodial lending protocol deployed on many chains, offering deposits and borrowing across a wide range of assets.
• Morpho is a lending protocol built around isolated markets and curated vaults, which can separate risk by market.
• Euler V2 is a modular lending protocol where market curators set up their own lending markets.
• SparkLend is a stablecoin-focused lending market on Ethereum and Gnosis with rates set through governance.
• Liquity V2 is a borrowing protocol where users mint the BOLD stablecoin against ETH and other collateral and set their own interest rates.

Compound's appeal is its long track record and relatively straightforward market structure. Other protocols may offer more assets, more chains or more specialized risk tools. Compare the mechanism, not only the headline rate.

Several of the risks that apply to any DeFi lending protocol are worth understanding before you commit funds.

• Smart contract risk: code can contain bugs or be exploited, even after audits.
• Oracle risk: prices used for collateral valuation may be wrong or delayed.
• Liquidation risk: sharp market drops can close a loan at a loss.
• Liquidity risk: withdrawals may be restricted when a pool is heavily borrowed.
• Governance risk: parameter changes can alter your position's terms.
• Stablecoin and asset risk: collateral or supplied tokens can lose their peg or value.

None of these risks can be removed entirely. Reducing exposure means keeping loans conservative, diversifying across protocols where it makes sense, and never committing more than you can afford to lose.

A cautious first approach looks like this:

1. Read the protocol's official documentation and confirm the version and network you are using.
2. Check the official website address through a trusted source rather than a search result or unsolicited message.
3. Use a wallet you control and never share your seed phrase or private keys with anyone.
4. Start with a small amount so you can see how supply, interest and withdrawals work.
5. Before borrowing, calculate the price drop your collateral could absorb before liquidation.
6. Read each transaction request carefully, especially token approvals, and revoke approvals you no longer need.

For a deeper look at how Compound fits into the wider Ethereum DeFi space, compare its design with the protocols listed above. Doing so helps you see which features matter most for your goals.

This is general information, not financial advice. Crypto lending can lose value, and you should check the rules that apply where you live before using any service.