Item Pools

What Are Item Pools?

Item Pools are always-open markets between pairs of items. No order book, no waiting for a matching buyer: each pool holds a reserve of two items, and you trade one for the other directly against the pool, at a price set by the balance of its reserves. Anyone can swap, and anyone can deposit items into a pool to earn a cut of every trade that passes through it.

You can open the Item Pools window two ways:

• The Trading menu → Item Pools, from anywhere

• Clicking the fountain itself, at the Scrapyard exit

The window always shows the full list of pools currently live, along with each pool's reserves and swap fee.

Swapping

Pick a pool, enter how much you want to sell, and the window quotes what you'll receive. If the quote looks good, confirm, and the trade executes immediately.

A few things worth knowing:

• Price moves with size. A pool's price comes from the ratio of its two reserves, just like regular liquidity pools, so bigger trades shift the price against you as they go. Small trades get very close to the quoted price; enormous ones will not.

• Prices are quoted in MUSU whenever MUSU is one of the pair. Item-for-item pools quote in whichever direction you're swapping.

• Slippage protection is automatic. Your swap fails safely rather than filling at a meaningfully worse price than quoted (the window allows up to a 1% drift).

• Every pool charges a swap fee, shown in the window. The fee doesn't go to the house, it goes into the pool's reserves, which is what pays the liquidity providers below.

Providing Liquidity

If swapping is using the fountain, providing liquidity is being the fountain.

On the Liquidity tab you deposit both items of a pair, at the pool's current ratio, and receive LP shares representing your slice of the pool. From then on, every swap anyone makes in that pool pays its fee into the reserves you co-own. When you withdraw, you burn your shares and receive your proportional slice of both reserves, fees included.

• You can add liquidity to any live pool at any time.

• You can withdraw at any time. This works even if a pool has been paused: swapping and depositing can be disabled, but exits always remain open. Your items cannot be trapped.

• If a pool is ever retired entirely, every remaining provider is automatically paid out their full slice at the final ratio.

A Word On Risk

Providing liquidity is not a savings account, it's a position. Two things to understand before you deposit:

• You will probably not get back the same mix you put in. As people swap, the pool's ratio shifts, and your slice shifts with it. Deposit 50/50 and you may withdraw 70/30, because the pool automatically sells whichever item is being bought up.

• If one item's price moves a lot, fees may not cover the difference. This is the effect known elsewhere as impermanent loss: a liquidity position in a pool whose price moved can be worth less than if you had simply held the two items in your bag. Fees offset this, and busy pools offset it more, but it is not a guarantee.