What is DeFi (decentralised finance)?
Written by an ex-institutional trader. What DeFi is, how smart contracts replace the middleman, what you can actually do with it, how it compares to traditional finance, and the risks that are easy to underestimate.
Direct answer
DeFi, or decentralised finance, is financial services like lending, borrowing, trading and earning yield, run by code (smart contracts) on a blockchain instead of by banks or brokers. There is no company in the middle: the rules are written into self-executing contracts, mostly on Ethereum, and anyone with a wallet can use them directly. It aims to recreate the financial system in an open, permissionless form where you keep custody of your own assets.
The appeal is access and control: no gatekeepers, 24/7 markets, and you hold your own funds. The trade-off is that there is no safety net. Smart-contract bugs, hacks, scams and the absence of any regulator or insurance make DeFi genuinely high-risk, and "yields" that look too good usually are. In Australia, DeFi activity is also taxable and the record-keeping is complex. Treat DeFi as the experimental, high-risk frontier of crypto, not a substitute for a bank.
What DeFi is
DeFi, short for decentralised finance, is financial services like lending, borrowing, trading and earning yield, run by code on a blockchain instead of by banks or brokers. The rules are written into smart contracts, self-executing programs, mostly on Ethereum, and anyone with a crypto wallet can use them directly with no company in the middle.
The ambition is large: to rebuild the financial system in an open, permissionless form where there are no gatekeepers and you keep custody of your own assets. The reality is a powerful but high-risk frontier where the absence of a middleman also means the absence of a safety net.
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How it works
The engine of DeFi is the smart contract: a program deployed on a blockchain that runs automatically when its conditions are met. Instead of a bank approving and managing a loan, a lending contract holds deposits, lends them out, and enforces the collateral rules in code, with no human in the loop.
You use DeFi by connecting your wallet to an app and approving transactions. Because the contract lives on a decentralised network, no single party can stop it or quietly change the rules once it is live. That is its strength, and also its danger: if the code has a bug, there is no one to halt it before the funds are gone. Most DeFi runs on Ethereum, whose programmable blockchain made smart contracts practical.
What you can do with it
The main DeFi activities mirror traditional finance, minus the institutions:
- Lending and borrowing. Deposit assets to earn interest, or borrow against crypto collateral, through lending protocols.
- Decentralised exchanges (DEXs). Swap tokens directly from your wallet without a centralised exchange holding your funds.
- Liquidity providing. Supply pairs of tokens to a pool and earn a share of trading fees, with the risk of impermanent loss.
- Stablecoin yield. Earn returns on stablecoins, though high advertised yields signal high risk.
All of these keep you in custody of your assets via your wallet, which is the defining DeFi feature.
DeFi vs traditional finance
| Feature | DeFi | Traditional finance |
|---|---|---|
| Middleman | None, code enforces rules | Banks, brokers, institutions |
| Access | Anyone with a wallet, 24/7 | Approval, hours, jurisdiction limits |
| Custody | You hold your own funds | The institution holds your funds |
| Protection | None; no insurance or regulator | Regulated, often insured |
| Recourse if it goes wrong | Usually none | Disputes, regulators, courts |
| Risk level | High | Lower |
The trade is stark: DeFi gives you control and access in exchange for removing every safety net. That suits some experienced users and is genuinely dangerous for the unprepared.
The risks
DeFi concentrates most of crypto's risks in one place:
- Smart-contract exploits. Bugs have drained billions. Even audited code is not guaranteed safe.
- Scams and rug pulls. Anonymous teams launch projects, attract deposits, then disappear.
- No safety net. No regulator, insurance, or support. Mistakes and hacks are usually irreversible.
- Unsustainable yields. Eye-catching returns almost always carry hidden risk of losing the principal.
For most people, centralised AUSTRAC-registered exchanges are the sensible place to engage with crypto, and DeFi is an advanced, high-risk step to approach carefully and only with money you can afford to lose. Remember DeFi activity is also taxable in Australia and the record-keeping is involved.
Popular Australian crypto exchanges
All three are AUSTRAC-registered Australian exchanges. Crypto is volatile; only invest what you can afford to lose.
This is general information, not financial advice. DeFi is high-risk. Last reviewed: 2026-06-02.
Frequently asked questions
What is DeFi in simple terms?
DeFi (decentralised finance) is financial services that run on a blockchain through code instead of through banks or brokers. Lending, borrowing, trading and earning interest all happen via smart contracts, self-executing programs that enforce the rules automatically, with no company in the middle. Anyone with a crypto wallet can use them directly, keeping custody of their own funds. It is an attempt to rebuild the financial system in an open, permissionless form, mostly on the Ethereum blockchain.
How does DeFi work?
DeFi runs on smart contracts: programs deployed on a blockchain that execute automatically when their conditions are met. Instead of a bank approving a loan, a lending contract holds deposits, lends them out, and enforces collateral rules in code. You interact by connecting a crypto wallet to a DeFi app and approving transactions. Because the contract runs on a decentralised network, no single party can stop it or change the rules once deployed, which is both its strength and, when there are bugs, its danger.
Is DeFi safe?
DeFi is high-risk. There is no bank, regulator, insurance or customer-support line, so if a smart contract is hacked, a project is a scam, or you make a mistake, there is usually no recourse and no way to reverse it. Smart-contract exploits have drained billions of dollars, and the space is full of scams and unsustainable yields. Even well-audited protocols carry risk. DeFi can be used carefully by experienced people, but it is the frontier of crypto, not a safe place for money you cannot afford to lose.
What is the difference between DeFi and CeFi?
CeFi (centralised finance) means crypto services run by a company that holds your funds, such as a centralised exchange where you buy and sell crypto. DeFi (decentralised finance) means services run by code where you keep custody of your own funds via your wallet. CeFi is more convenient and beginner-friendly but requires trusting the company; DeFi removes the company but puts all responsibility, and risk, on you. Most people start with CeFi exchanges and only some venture into DeFi later.
Can you make money with DeFi?
Some people earn returns through DeFi by lending assets, providing liquidity, or staking, but the headline yields are not free money, they reflect real risk. Returns can be wiped out by smart-contract hacks, token price crashes, impermanent loss when providing liquidity, or outright scams. Extremely high advertised yields are a red flag, not an opportunity. Any DeFi return should be weighed against the genuine chance of losing the entire principal, which is much higher than in traditional finance.
Is DeFi taxable in Australia?
Yes, and the record-keeping is complex. The ATO generally treats DeFi activity as taxable: swapping tokens, earning yield, and many lending and liquidity actions can trigger capital-gains or income tax events. Because DeFi can generate hundreds of small transactions, tracking it manually is very hard, which is why crypto tax software that connects to wallets and protocols is widely used. See the DeFi tax and crypto tax guides for how the ATO treats specific DeFi activities.
