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 reality is that between 2020 and 2022 I personally made several times my entry capital in DeFi, and then handed roughly half of it back in a single bad season. This is the hands-on walkthrough of what DeFi actually is, what risks are real, and — for the second half of the piece — what the US and European reader specifically needs to think about.

§1 · DeFi in three operations

Operation 1 · Lending and borrowing

I have 1 ETH. I would like to borrow some USDC against it. During the 2020 DeFi summer, yield farms were quoting 1,000% APR on some pools and others would rug-pull within 72 hours; group chats lit up at 4am with "this one is exiting, switch out now." 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. This is the single most common way DeFi users lose money in 2024-2026 — not protocol hacks, but approve-drainer phishing.

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 · How I made money in DeFi summer 2020

June 2020. Compound launched its COMP token, distributed based on borrowing and lending activity. You used Compound, you got COMP. I had a small unused balance, threw 1,000 USDC in to test. A week later my account had about $50 worth of COMP added on top of the normal lending APY. Annualized: over 200%.

My first instinct was that this was a bug. A friend explained: "No, this is yield farming. It is the new design pattern." Over the next three 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 pulled half its liquidity overnight. Andre Cronje single-handedly seeded the Fantom DeFi ecosystem with farm-and-dump tokens that did 100× then went to zero.

My personal pattern was simple. Farm a protocol's token, sell partial when it ran, keep some staked to continue earning. Through the second half of 2020 my base capital roughly 4×'d. Did I step on rug pulls? Yes, several times. The pattern of "new protocol day, exit by day five" meant losses on individual plays were capped while winners ran. The whole environment was structurally asymmetric — small losses, large gains. That asymmetry does not exist in 2026. Do not assume it is the default.

§3 · How I gave half of it back in 2022

May 2022. The LUNA collapse. I have written about my small LUNA bag elsewhere. What I have not written about — until now — is the LUNA-adjacent position that was much more damaging: my UST deposit on Anchor Protocol. Anchor paid 20% APY on UST deposits. I had several thousand UST parked there, telling myself it was "passive yield on a stablecoin." Both halves of that sentence turned out to be wrong.

When UST depegged, the Anchor deposit went to zero. Not because the deposit interface broke — the interface still worked — but because the unit of account, UST itself, was worthless. My 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 depegged from ETH. I held stETH in a Lido position — Lido was supposed to be one of the safest yield strategies in DeFi. The discount went to 5-8% and it took weeks to swap out at anything close to par. Across 2022, my DeFi portfolio dropped more than half from its peak. Most of what I had earned in 2020 went back to the market through 2022.

I learned a sentence I will not forget: the market eventually teaches you whatever it has decided to teach you. The tuition is just expensive.

§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:

Cumulative DeFi-related losses now exceed $10B. 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:

More than 90% of new tokens launched on DEXs in any given month go to zero by the following month. The most common rookie mistake: chasing 200%+ APY on a new pool. That 200% is not "yield." It is the half-life of the project in days.

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: when ETH crashed 50% in a day, network gas spiked above $200 per transaction, and MakerDAO's liquidation bots could not afford to bid. Some collateralized debt positions were auctioned at zero ETH — meaning the auction winner paid nothing, took the entire vault, and the borrower received 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, then partially de-listed by a federal court ruling in 2024, then re-evaluated by the Treasury through 2025. If you have transacted with Tornado-tainted addresses, you may face compliance issues 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 · US & European reader perspective

DeFi mechanics are the same everywhere. But your access, your legal exposure, and your tax treatment are dramatically different depending on whether you sit in the US, the EU, or anywhere else. This section is the part that does not appear in the Chinese-language version of this article.

Uniswap, Aave, Curve · which protocols are US-accessible

The major protocols' US posture as of early 2026:

The Gensler-to-Atkins SEC shift

From 2021 through 2024 the SEC under Gary Gensler treated essentially every DeFi token as a probable unregistered security. The Wells Notice to Uniswap Labs in April 2024 was the highest-profile escalation. With the second Trump administration's nomination of Paul Atkins as SEC chair in 2025, the posture changed materially. Crypto enforcement has been de-prioritized. The "Crypto 2.0" task force is drafting clearer registration paths. Several pending cases (including the Coinbase suit) have been narrowed or dropped. For a US DeFi user, the practical implication is: front-end providers are now less likely to geo-block US users out of pure regulatory caution. The protocols themselves remain permissionless; the user experience around them is improving. The longer-term durability of this regime depends on the next election cycle; treat it as a slow-moving variable, not a permanent shift.

DeFi tax in the US — the nightmare nobody warns you about

The US IRS treats DeFi activity with maximum severity. Every taxable event is real and reportable. The structurally painful items:

Practical consequence: an active yield farmer in a taxable account can easily generate thousands of taxable events per year, with the tax preparation alone costing four-figure dollars in CoinTracker / Koinly / TokenTax subscriptions and CPA time. For US readers, the math frequently favors "buy and hold mature, low-turnover DeFi positions" over "high-velocity yield farming" — the after-tax return on the second strategy is usually dramatically worse than the pre-tax return suggests.

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. A $100M exploit on a fully-covered protocol may pay claims at 30-50% of insured loss if it would exceed the mutual capacity. 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."

US best practices for DeFi in 2026

EU readers · MiCA and DeFi access

MiCA's text explicitly carved out fully-decentralized protocols from the CASP authorization requirement, but ESMA and individual national regulators have been writing implementation guidance that effectively requires front-end providers to comply if they have a clear operating entity in the EU. What this means in practice for an EU DeFi user:

The renewed custody debate after the Bybit hack

In February 2025, Bybit suffered the largest single crypto theft to date — $1.5B drained from a multisig wallet in what was attributed to a Lazarus Group operation that compromised the signing infrastructure. Bybit covered the loss from its own treasury and customer balances were made whole within days, 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, hardware-wallet purchases (Ledger, Trezor, Coldcard, Keystone) reportedly hit multi-year highs in both US and EU markets. 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. The structural arrow points one direction.

§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" — 100% phishing. No real service ever needs your seed.
4. Any "click to claim your airdrop" link — 90%+ are approve-drainer phishing.
5. Any stranger DM-ing you about a "private beta" — do not connect your wallet.

§7 · Where DeFi is going

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 launched permissioned institutional pools through Aave Arc. 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 4-8% as the new normal on stablecoin lending, not 20%. The 2020 DeFi summer was a one-time bootstrap event, not a baseline.

§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 current DeFi allocation is light. The core of my crypto stack is still BTC and ETH in self-custody, with DeFi accounting for 5-10% of my total exposure, concentrated in Aave, Uniswap, Curve and Sky. The 2022 lesson is one I plan to keep learning from for a long time.

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