DeFi is short for Decentralized Finance. Said another way: financial services with no bank, no broker, no intermediary — just smart contracts running on a public blockchain. That sounds romantic. The risk is just as real: the 2020 yield-farming boom and the 2022 LUNA/UST collapse saw the same set of protocols hand out gains quickly and then take them back just as fast. This is a walkthrough of what DeFi actually is, what those two periods looked like, and which risks are real.

§1 · DeFi in three operations

Operation 1 · Lending and borrowing

I have 1 ETH. I would like to borrow some USDC against it. A traditional bank would require credit history, identification, sometimes a co-signer, and a week of paperwork. DeFi: I open Aave, deposit 1 ETH (worth $3,000 in this example), and immediately borrow up to ~$1,500 USDC against it. Nobody asks me who I am. The smart contract only cares about the collateralization ratio.

The major lending protocols you should know: Aave, Compound, Maker (which mints DAI/USDS), Morpho, Spark, and Sky (the rebranded MakerDAO). The mechanic is universal: if your collateral falls below the threshold, the contract automatically liquidates you. Your ETH gets sold to repay your borrow, and the liquidator takes a 5-10% fee. There is no grace period and no phone call.

Operation 2 · Decentralized exchanges (DEX)

Centralized exchanges (Binance, OKX, Coinbase) are custodial. Your coins sit on their servers. They match your orders. If they fail or run, you may lose your balance — the FTX collapse is the canonical example. DEXs are different. Every swap happens on-chain. Your coins never leave your own wallet until the moment they swap into the other token.

The major DEXs in 2026: Uniswap (Ethereum + L2s), Curve (stablecoin-specialized), PancakeSwap (BSC), Balancer (multi-asset pools), Raydium (Solana), and Aerodrome (Base). Most modern DEXs use Automated Market Makers (AMMs) instead of order books — a pool holds two tokens, the ratio determines the price, anyone can swap. Uniswap V3 introduced concentrated liquidity (LPs pick a price range to provide liquidity in), and Uniswap V4 in 2024 introduced "hooks" — custom logic that runs at swap time, enabling new market designs.

DEXs' biggest virtue: no listing committee. Any token can trade on a DEX from the day it is deployed. That makes them the natural home for new and long-tail tokens. The downside: every transaction is a manual signature in your wallet. Sign a malicious approve, and you have given a contract permission to drain your tokens. For ordinary users, approve-drainer phishing is the risk to guard against every day: one careless signature is all it takes.

Operation 3 · Liquidity provision and yield farming

You deposit your tokens into a pool, and the pool pays you two kinds of yield: a share of trading fees (real, based on actual usage) and, often, additional emissions of the protocol's governance token (printed by the protocol to bootstrap liquidity). During the 2020-2021 peak, APYs of 50%, 200%, even 1,000%+ were common on new launches.

But this is not free money. Most of that yield is being paid in tokens that the protocol is printing to subsidize liquidity. If the token's price falls faster than the yield, you lose money even while showing positive "APY." The 2020 DeFi summer is named that because liquidity mining was discovered as a viable bootstrapping mechanic, drawing capital in waves and creating what's now called DeFi 1.0. The 2021-2022 unwind taught a generation of users that printed yield is not the same as earned yield.

§2 · Why did yield farming suddenly take off in 2020?

June 2020. Compound launched its COMP token, distributed based on borrowing and lending activity. You used Compound, you got COMP. As COMP's price climbed, the rewards on top of normal lending rates pushed annualized returns to absurd levels for a while — this is when the phrase yield farming took off.

Over the next few months every new DeFi protocol copied the model. Yearn launched YFI, which ran from $0 to $40,000+ — at one point worth more per token than BTC. Sushi forked Uniswap directly and used token incentives to pull a large share of Uniswap's liquidity.

The common playbook was simple: farm a protocol's token, sell part of it when it ran, keep some staked to continue earning. Plenty of protocols were rugged or exploited within days of launch. Still, in that market, losses on individual plays tended to be small while the winners ran — small losses, large gains. That kind of environment is rare. Do not assume it is the default; 2022 took a lot of those paper gains back.

§3 · What happened with LUNA and the stETH discount in 2022?

May 2022. The LUNA / UST collapse. The biggest draw in the UST ecosystem was Anchor Protocol, which paid around 20% APY on UST deposits. It looked like passive yield on a dollar deposit.

When UST depegged, Anchor deposits went to zero. Not because the deposit interface broke — the interface still worked — but because the unit of account, UST itself, was worthless. Principal disappeared along with the yield. The protocol did not "fail" in the conventional sense. The asset just became dust.

Then in June 2022, stETH traded at a clear discount to ETH. Staked ETH could not be withdrawn yet, so the only way back to ETH was to sell stETH on the secondary market at a discount — and positions that used stETH as borrowing collateral came under pressure too. Across 2022, DeFi asset prices and total value locked fell sharply, and much of what had been earned in 2020–2021 went back to the market.

§4 · The five major risks in DeFi, one by one

Risk 1 · Smart contract bugs and exploits

DeFi protocols are just code. Code has bugs. Bugs get exploited. Once a contract is drained, the funds are visible on-chain but generally not recoverable. The historical hit list, partial:

Added up over the years, DeFi-related losses are very large. Any DeFi protocol you touch carries non-zero risk that you wake up to zero balance. The mitigation: stick to mature, multi-year, multi-audit, large-TVL protocols. Aave, Uniswap, Curve, Lido, MakerDAO/Sky have all survived multiple cycles. The "200% APY new farm" you saw on Twitter has not.

Risk 2 · Rug pulls

A "rug pull" is the founder team draining the project. Variants in 2024-2026:

A large share of the new tokens launched on DEXs end up worthless, many of them within weeks. Don't chase 200%+ APY on a new pool. Yields like that are usually paid in freshly printed tokens; once the token gets dumped, the yield and your principal shrink together.

Risk 3 · Impermanent loss

The hardest risk to explain, and the one most LP newcomers do not fully understand. Simplified version: when you provide liquidity as 50% ETH and 50% USDC, and ETH price moves significantly, the value of what you can withdraw is less than what you would have had by just holding the original ETH and USDC. The pool's automated rebalancing is what causes the gap.

Concrete example. You deposit 1 ETH (worth $2,000) + 2,000 USDC into a pool — total $4,000. ETH rises to $4,000. When you withdraw, you receive approximately 0.71 ETH + 2,828 USDC = about $5,656 total. Pure HODL would have given you 1 ETH + 2,000 USDC = $6,000. The $344 gap is impermanent loss. When trading fee yield is high, IL can be more than offset. When fees are low and prices are volatile, IL will burn through your principal. Do not provide liquidity until you can do the IL math yourself for a given pool and price scenario.

Risk 4 · Forced liquidation

DeFi lending's defining mechanic: collateral below threshold gets sold by liquidators, who keep a 5-10% bounty for executing the liquidation. Your loss is therefore greater than the bare price drop in the collateral.

March 12, 2020 — sometimes called "Black Thursday" in DeFi — is the canonical disaster: ETH crashed, the network clogged, gas prices exploded, and many of MakerDAO's liquidation bots failed to bid. Some vaults' ETH collateral was won with bids of zero DAI — the winner paid nothing for the collateral, and the borrowers got nothing back. The liquidation system itself broke under stress. In extreme conditions, the protective mechanism you are relying on may not work.

Risk 5 · Regulatory and bridge risk

Regulatory: Tornado Cash was sanctioned by US OFAC in August 2022; in March 2025 the US Treasury removed it from the sanctions list. Exchange risk systems can still flag addresses that interacted with it, so if you have received funds from Tornado-linked addresses, you may be asked to explain the source — or refused — at regulated off-ramps. Several DeFi protocols (including Uniswap, Aave) have implemented front-end geo-restrictions to comply with US enforcement guidance.

Bridge risk: cross-chain bridges have been DeFi's single most exploited category by dollar value. Multichain collapsed in 2023, Nomad was drained in 2022, Wormhole was hit in 2022, Ronin was the largest at $625M. Bridges have to hold enormous custodial balances, which makes them the highest-EV target for any sophisticated attacker. Cross-chain only when you genuinely need to, and always use the longest-running and best-audited bridge available for the pair.

§5 · How do you limit the damage when something goes wrong in DeFi?

DeFi mechanics are the same everywhere. What you can control is how much damage a single mistake or exploit can do to you.

DeFi insurance · what coverage actually exists in 2026

Three protocols offer DeFi-specific cover: Nexus Mutual, InsurAce, and Sherlock. Coverage is real but capped (each protocol covered up to a fixed dollar amount in mutual capital), specific to enumerated risks (smart contract exploit, oracle failure, stablecoin depeg, custodial failure), and excludes user error (you sign a malicious approve, no insurance pays). The practical issue is mutual capital is limited. If a large exploit produces more claims than the pool can cover, payouts can come in well below the insured loss. For most retail users, DeFi insurance is something to layer on top of, not rely on as primary protection. The primary protection is still "don't put more than 10-20% of your stack in any one protocol."

Best practices for DeFi in 2026

The renewed custody debate after the Bybit hack

In February 2025, Bybit suffered the largest single crypto theft to date — about $1.5B drained from a multisig wallet in what was attributed to a Lazarus Group operation that compromised the signing infrastructure. Bybit said client assets remained fully backed, and it closed the gap within days, partly with bridge loans, but the incident reopened a broader debate that DeFi-native users have been having for years: centralized custody is a single attack surface; multisig self-custody distributes attack surface but introduces signature complexity. Net effect: by mid-2025, interest in hardware wallets (Ledger, Trezor, Coldcard, Keystone) had picked up noticeably. The pattern repeats: every large custodial failure pushes incrementally more capital toward self-custody — Mt.Gox in 2014, the 2022 CeFi-lender wave, FTX, Bybit.

§6 · Should a new user touch DeFi at all?

My answer · try with money you can lose, and learn the mechanics

DeFi is the most genuinely innovative part of crypto. It is the only place where the "financial services as code" thesis actually got executed at scale. Until you have used it yourself, you will not understand what makes it powerful and what makes it dangerous.

But the gating condition is that you only use money you can fully tolerate losing. Start with $50 to $100. Do one Uniswap swap end to end. Do one Aave deposit. Watch the on-chain interest accrue in real time. Once you feel the interface and have signed a few transactions, then start considering larger amounts.

A new-user-friendly entry path

  1. Install MetaMask (or the wallet of your choice — see the wallet article). Move a small amount of ETH from your exchange to it.
  2. One Uniswap swap: convert ETH to USDC. Pay attention to the gas fee. Feel what "no account needed, anyone can swap" actually means.
  3. One Aave deposit: deposit $50 USDC. Watch interest accrue. Get comfortable with the deposit/borrow UI.
  4. Avoid these three things for at least 6 months: high-APY pools, liquidity provision, and any small or new protocol. These are where new users go to lose.
⚠ DeFi anti-scam red lines

1. Any APY above 30% — be skeptical. Real range is 3-15%.
2. Any small protocol asking you to "approve unlimited spend" — close the tab.
3. Any site asking for your seed phrase "to verify" — always phishing. No real service ever needs your seed.
4. Any "click to claim your airdrop" link — most are approve-drainer phishing.
5. Any stranger DM-ing you about a "private beta" — do not connect your wallet.

§7 · Does DeFi still have a future?

My view: DeFi is not going to die, but it is not going back to the wild 2020 growth either. The dominant force shaping it now is compliance. The maturing DeFi protocols increasingly look like traditional finance — KYC layers, permissioned pools, institutional-grade fronts. Uniswap already geo-blocks certain tokens. Aave has also run a permissioned version aimed at institutions. This is the direction.

Fully permissionless DeFi will continue to exist, but it will be increasingly orthogonal to mainstream regulation. The likeliest split: regulated institutional DeFi grows into a real settlement infrastructure layer used by banks and asset managers, while permissionless retail DeFi continues as its own parallel system.

For a new user, the consequence is: as long as you stick to the mature protocols (Aave, Uniswap, Curve, Lido, MakerDAO/Sky), you are along for the ride as those protocols progressively de-risk through compliance. Yields will compress further — assume single-digit yields as the norm on stablecoin lending, and forget about 20%. Treat the 2020 DeFi summer as a one-off bootstrap period; it tells you nothing about normal returns.

§8 · Closing thoughts

DeFi is the most fascinating and most punishing area of crypto, simultaneously. The upside: financial services without permission gates — anyone, anywhere, can lend, swap, earn yield without a bank account. The downside: the risk is at least an order of magnitude higher than the equivalent traditional service — hacks, exploits, rug pulls, regulatory shocks, all live.

My advice for a new user: keep DeFi a small slice of what you hold, start with long-running protocols like Aave and Uniswap, and get the mechanics and the risks straight before you size up.

Before you do anything else, read the wallet article next. Without self-custody, you cannot even take the first step into DeFi safely.