Uni’s shop only worked because people lent it their tuna and rice. These lenders were called liquidity providers, and for every bowl they lent, Uni gave them a receipt, an LP token, which they could swap back later for their share of the pool, plus all the little tips that had piled up.

The Chef had a plan. “Bring your Uni receipts to our kitchen,” the Chef announced. “Leave them with us, and we’ll pay you in SUSHI every single block.” Lots of people did. Then, one night in September, the Chef flipped a switch.

All at once, the receipts were cashed in at Uni’s shop and the bowls were carried next door. Rolls by the hundred, bowls in their little arms, marching down the street under the moon. Uni stood in the doorway and watched hundreds of millions of dollars’ worth of rice walk past.

“Why would anyone give you their bowls?” asked Maki, watching the belt go round.

“Because of the receipts,” said the Chef. “When you add tuna and rice to a pool, in the right balance, you get an LP token. It says you own, say, 2% of this pool. Every swap leaves a tip behind in the pool, so the pool grows, and your 2% grows with it.”

“And when you want your bowls back?”

“Hand back the receipt. You get 2% of whatever tuna and rice are in there now.” The Chef paused. “Which is not always the same as what you put in. But that’s a sad story for later.”

Now it’s your turn to be a liquidity provider. The tuna–rice pool already has some bowls in it. Add your own, in the same balance as the pool, and see what share of the pool your receipt says you own.

Then let a day of swaps go by. Each swap drops its tiny tip into the bowls, and your receipt quietly becomes worth a little more.

Uni, next door, was not having a good week. But Uni was about to have a better one than the Chef.