By the end you will understand the machine that closes other people's loans, why strangers race all night to do it, and how one red hour feeds on itself.
You met a liquidation once already. In checkpoint 2, a CEX seized a levered trader at 3am, sold the position, and the price came back by morning. That was a venue's machine, behind closed doors.
Last checkpoint left a question open: the pawnshop lends against volatile collateral, and when that collateral thins, the pool's lenders are the ones exposed. Someone must close the failing loan, and nobody is on duty. A TradFi broker would phone you. This pawnshop has no phone.
Function first. Every loan on the books is a ratio: what the collateral is worth right now, against what the loan requires it to cover. While the ratio sits above one, the loan is nobody's business. The moment it slips below the line, the loan becomes seizable.
The name protocols give this ratio: the health factor. It is not a credit score, and no human reads it. It is recomputed every time the price moves, on every loan in the city, all night.
ETH slides and the card rewrites itself. The debt did not grow; the collateral thinned, so the health sank toward the line. Three things can move a health factor, and only two of them are yours.
Try each lever and watch the health respond.
Suppose the card crosses the line at 3am. In TradFi, a broker phones you: add funds by noon or we close the position. This pawnshop knows no phone number, employs no loan officers, and cannot wait for noon. Its lenders are exposed every minute the loan stays open.
So before the reveal, place your bet: who actually does it?
Here is the offer. Anyone may step in, repay a failing loan's debt, and take collateral worth more than they paid. The books call that gap a liquidation bonus; plain chalk calls it a bounty. It is why liquidation bots exist and why failing loans close in seconds.
So who is paying? The borrower. The discounted collateral comes out of their side of the card, on the worst day of their month. The bounty is not a fine. It is the wage of an all night guard the pawnshop never has to hire.
It is easy to hate the stranger who took your collateral at 3am. Be honest about the roles anyway. Fast liquidation is what makes the pool's lenders whole, and lenders who trust the machine accept lower rates. A lending market that hesitates to close bad loans dies.
The bounty hunter is infrastructure wearing a villain's face. Nothing noble, nothing sinister: a role the machine needs filled, filled by whoever races fastest. The same stranger is the borrower's worst morning and the reason the desk was open at all.
Now run the machine under stress. A hard drop pushes a whole tier of loans below the line at once. Bounty hunters close them, and closing them means selling seized collateral into a market that is already falling.
That selling pushes the price lower, which trips the next tier. This pattern shows up in every major crash: a mechanism, not a conspiracy. Trace the loop.
Checkpoint 2 showed you this night from a CEX trader's side. Now it happens on chain, with the machinery visible. During the red hour your loan crossed the line; a bot repaid your debt and took discounted collateral. By breakfast the price is back above your line.
You were right about the market. So what is your position?
Zoom out. The pawnshop from checkpoint 10 only stays solvent because this machine stands behind it: a ratio on every loan, a bounty on every failure, strangers racing to collect. One test before we finish: after a red hour, is the machine broken?
Take stock. Borrowers here live like pilots: margin above the line, alerts set, and the humility to know that a routine wiggle, checkpoint 2's oldest lesson, arrives on chain too. The health factor is the altimeter, and nobody flies at the treetops twice.
You now know the machine that keeps lending solvent: the ratio, the bounty, the racing strangers, the loop. But everything so far assumed one thing quietly: a dollar that stays a dollar. Next: the machines that manufacture stability itself.