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What is DeFi?

Written and maintained by the BTCNATOR editorial team • Last updated September 8, 2026 • How we research

Quick answer

DeFi (decentralised finance) is financial services built as smart contracts on public blockchains — trading, lending, borrowing, earning yield — with no bank, broker or exchange company in the middle. Anyone with a wallet can use it directly. That openness removes gatekeepers, but it also removes the safety nets: there is no customer support, no deposit insurance, and no one to reverse a bad transaction.

Detailed explanation

In traditional finance, a company holds your money and runs the rules. In DeFi, the rules are code that runs on a blockchain, and you keep custody of your assets in your own wallet while interacting with that code.

Common building blocks: DEXs for swapping tokens, lending protocols where you supply assets to earn interest or borrow against collateral, stablecoins that track a currency like the US dollar, and liquidity pools that provide the capital those services use.

How it works

  1. You connect a self-custody wallet to a DeFi app (a "dApp").
  2. You approve the app’s smart contract to use a specific token.
  3. You send a transaction that deposits, swaps, lends or borrows.
  4. The contract executes automatically and updates balances on-chain.

Every step is a blockchain transaction with a network fee, and every step is final once confirmed.

Key facts

  • DeFi services are smart contracts, not companies.
  • You keep custody: assets stay in your wallet until a contract moves them with your signed approval.
  • There is no support desk, chargeback, or insurance on a bad transaction.
  • Yields advertised by DeFi apps are variable and not guaranteed.
  • Contract code is public; that does not mean it is bug-free or safe.

Risks and limitations

  • Smart-contract bugs and exploits can drain funds with no recovery.
  • Token approvals can be abused — review and revoke approvals you no longer need.
  • "Impermanent loss" can leave liquidity providers worse off than simply holding.
  • Borrowing against volatile collateral can trigger automatic liquidation.
  • Scam apps and fake token contracts are common; verify contract addresses.

FAQ

Is DeFi the same as crypto?
No. Crypto is the broader category. DeFi is one use of it: financial applications running on public blockchains.
Do I need an account for DeFi?
No. You use a self-custody wallet. There is no sign-up, but also no one to help if something goes wrong.
Is the yield safe?
No yield in DeFi is guaranteed. Rates move constantly, and the capital itself is exposed to contract and market risk.
Can DeFi transactions be reversed?
No. Like any blockchain transaction, they are final once confirmed.

Sources

Related topics

What is a DEX?What is a crypto wallet?What is a crypto swap?

This guide provides educational information about how cryptocurrency technology works. It is not financial, investment, legal, or tax advice. Cryptocurrency involves risk, including the potential loss of funds. Please review our editorial policy and methodology for more details.