Markets Lending

Here is why the fraction exists. A pawnshop cannot chase you: no address, no court, no phone number. So it protects itself the only way left. It lends less than the counter holds; if you walk away, it keeps your ETH and loses nothing.

Function first, now the names. The fraction of your collateral's value you may borrow is the loan-to-value, LTV for short, set per asset by how wildly its price swings. And the habit of always holding more than it lends is overcollateralization: the ledger you just read.

Why would anyone borrow against money they already have? Because selling ends the position. Borrowing unlocks cash while your ETH keeps riding, and in many places a loan is not a taxable sale. Traders also borrow to go long, or to run strategies this course meets later.

So this desk is a tool, not desperation. The person at the counter is usually not broke; they are keeping one hand on an asset while the other hand spends. Every loan here is somebody choosing not to sell.

One more secret: no lender ever meets a borrower. Depositors pour into one shared pool and earn from it; borrowers draw from that same pool and pay into it. The shop's shelves are the pool, stocked by strangers.

Which makes one number the shop's pulse: how much of the pool is currently lent out. Ninety five of every hundred out the door means nearly empty shelves. Function first; the name is utilization. Now bet: shelves nearly empty, what does the interest rate do?

Here is the machine's heart. No committee sets the rate; this curve does. Utilization runs left to right, and the borrow rate climbs with it: gentle while the shelves are stocked, then a sharp bend, then nearly vertical. The bend has a name, the kink.

Everything the shop wants from you is drawn in that shape. Tap the three zones to hear what each one is for.

Read the curve again and the rate stops looking like a price. It is a thermostat. Pool too full: the rate falls and borrowing warms up. Pool too empty: the rate spikes and money rushes home. The set point is the kink, and nobody ever touches the dial.

So who is paying? Borrowers pay the rate; lenders receive it, minus the protocol's cut for running the shop. Nobody subsidizes the middle. Every unit of yield a depositor earns walked in as interest from someone borrowing on the other side.

Now live the tension. You deposited USDC weeks ago; today you want it back, and utilization sits at 99 percent. The shelves hold one coin in a hundred. The board shows the shop at its worst hour.

Notice what nobody did: nobody decided this. A borrow rate here can triple overnight with no meeting, no email, no villain. The curve decided. Living with machine-set rates is the skill this desk demands. So, your withdrawal: what actually happens?

One test before we close the ledger. No credit checks, no paperwork, open all night: it is tempting to say this machine replaces banks. Two people walk up to the counter. One holds ETH and needs cash. One holds nothing and needs a start.

The machine, fully open. A counter that holds collateral instead of asking questions, a limit set as a fraction, one shared pool filled by strangers, and a rate that reads the shelves and moves by itself. Aave and Compound are this drawing with different handwriting.

One question is still open. Your loan is backed by what sits on the counter, and what sits on the counter is volatile. What happens when its value falls while the loan is out? Next: the machine that keeps the pawnshop solvent.