Finance, opened up

The DeFi guide.

Decentralized finance rebuilds banking as open software: lending, trading and earning, running day and night on the blockchain. Here is how it works, where it came from, and how to explore it with confidence.

Reviewed and current as of September 12, 2026

01What DeFi is

DeFi stands for decentralized finance. It is the collection of apps and protocols that offer financial services, lending, borrowing, trading, saving, through smart contracts on public blockchains. The code sets the rules, the blockchain enforces them, and anyone with an internet connection can participate.

Traditional finance asks you to trust an institution. DeFi asks you to read the code, and the code runs the same for everyone. Markets stay open around the clock, terms stay visible on chain, and settlement happens in minutes.

02Lending and borrowing, minus the bank

In a DeFi lending pool, savers deposit crypto and borrowers draw against it, all arranged by a smart contract. The contract sets interest rates from supply and demand: plenty of deposits with few borrowers means low rates, while heavy borrowing pushes rates higher.

Borrowers post collateral worth more than the loan, which keeps the pool healthy. If collateral value slides too far, the contract sells just enough to cover the loan automatically. Every step stays transparent: total deposits, total borrows and current rates sit on the blockchain for anyone to inspect.

03DEXs and centralized exchanges, side by side

A centralized exchange runs the order book, holds customer funds and usually asks for ID, offering the smoothest ramp from dollars to crypto. A decentralized exchange, or DEX, runs on smart contracts: you trade straight from your own wallet, keeping your keys the whole time.

Think of it as counter service and self service. Centralized venues offer deep order books, customer support and easy fiat on ramps. DEXs offer custody, privacy and access to brand new tokens the moment they launch. Many traders use both, matching the venue to the job.

04Liquidity pools and yield, in plain words

A liquidity pool is a shared pot of two tokens that lets traders swap instantly. Depositors, called liquidity providers, earn a cut of every trade that flows through. Prices inside the pool follow a simple formula, so markets stay open around the clock with the formula itself keeping both sides balanced.

Yield is the reward for putting crypto to work. It comes from trading fees, lending interest, staking rewards and protocol incentives. Rates move with demand, so seasoned users compare options, mind the fees, and treat eye popping headline numbers as invitations to read the fine print.

05The 2020 DeFi summer

In June 2020, the lending protocol Compound started rewarding users with its COMP token, and deposits flooded in. The idea, earn tokens for using a protocol, spread quickly. Total value locked in DeFi climbed from about one billion dollars early in the year to past ten billion by December, an estimate based on onchain data.

That summer turned DeFi from an experiment into an industry. New protocols launched weekly, yields soared, and builders learned lasting lessons about code quality at speed. The protocols that endured, audited, battle tested and transparent, became the foundation of everything that followed.

06Explore with good habits

Start with established protocols carrying public audits and long track records. Read the docs before you deposit, and begin with small amounts while you learn the ropes.

Keep your keys the way the security guide teaches: hardware wallet for savings, seed phrase on paper, test transactions first. Treat brand new launches promising instant riches as entertainment, and give every opportunity the overnight test. Caution is a strategy, and patient explorers last the longest.

07Keep learning on this site

The glossary explains liquidity pools, yield farming and every other term in plain language. The security basics guide covers the habits that keep your funds safe. And the Daily Brief reports what DeFi builders ship next, every morning.