Lending and borrowing — the bank window, without the bank.

I thought lending in DeFi meant sending money to strangers on the internet. Some protocols feel that way. The mainstream version is closer to a pool: you deposit assets into a smart contract, borrowers pay interest, you get a slice. No branch office, no credit check — collateral rules instead.

You deposit stablecoins or major crypto into a protocol like Aave or Compound. Borrowers pull from the pool and pay variable interest. You receive receipt tokens representing your share, which quietly accrue value as interest flows in.

Rates bounce around with demand. Quiet markets pay little. Chaotic markets pay more — often because borrowers are desperate, which should make you curious why.

Most beginners aren’t borrowing to buy a car. Common pattern: you already hold ether, you don’t want to sell (taxes, conviction, whatever), you deposit it as collateral and borrow stablecoins against it. You get liquidity without triggering a sale.

The catch is overcollateralization. Deposit $150 of ETH, borrow maybe $100 of USDC. If ETH drops hard, your collateral no longer covers the loan and the protocol liquidates you — sells your collateral automatically, often with a penalty. You can lose money even if you never sold a thing yourself.

Borrowing against crypto isn’t free money. It’s a bet that your collateral won’t fall faster than you can react.

Smart contract risk: the code holds the funds. Audits help; they don’t guarantee safety. Protocol risk: governance can change parameters. Oracle risk: price feeds can glitch or lag during crashes, triggering unfair liquidations.

As a lender you’re exposed to whether borrowers get liquidated cleanly and whether the protocol survives stress. As a borrower you’re playing a leverage game with a visible cliff.

Lending taught me more about risk than any whitepaper. Useful plumbing. Not a place for money you need back on a Tuesday.