Liquidity Iteration

When swapping through liquidity via a Multi-Hop Swap or a Taker Limit Order, we iterate through the available TickLiquidity to fill the swap order. Liquidity is always iterated through in order of best to worst price (from the taker's perspective.) For each swap, we completely exhaust the available reserves before moving on to the next tick. For TickLiquidity instances at the same TickIndex they are iterated through in a deterministic order as follows:

• PoolReserves take priority
• LimitOrderTranches are iterated through when Pool Reserve liquidity is depleted
• LimitOrderTranches are iterated through in alphabetical order of their TrancheKey (LimitOrderTranche.Key.TrancheKey.)

When swapping through PoolReserves the proceeds from the swap are added to the reserves on the reciprocal side of the pool. Ie. The output of TokenA swapped through a PoolReserves will be moved to a PoolReserves holding TokenB.

Example liquidity Placement

DEX Deposits (0 fee):

$$\text{Tick Index Formula}$$

$$\text{Price} = 1.0001 ^ \text{ -TickIndex}\\ \text{TickIndex} = -log_{1.0001}(price)$$

• Deposit 1:Amounts: 10 ATOM 10 USDC. Price: 10 USDC per ATOM. Tick index $-23027$.
• Deposit 2:Amounts: 10 ATOM 10 USDC. Price: 9 USDC per ATOM. Tick index $-21973$.
• Deposit 3:Amounts: 10 ATOM 10 USDC. Price: 8 USDC per ATOM. Tick index $-20795$.

DEX Limit Orders:

• Limit Order 1:Amount: 10 ATOM. Price: $0.14$ ATOM per USDC: Tick index $-19460$

• Tick Index $-23027$ offers the cheapest USDC per ATOM spent. it yields $10$ USDC per ATOM
• Tick Index $19640$ offers the cheapest ATOM per USDC spent. it yields $0.14$ ATOM per USDC
• It is visible that iterating left to right will always yield the best price regardless of the token being swapped.

Example Liquidity Iteration: Swap

Alice Performs a Swap using a Taker Limit Order. She wants to swap $100$ USDC for ATOM at the best possible price.

1. The first available TickLiquidity holding ATOM is a LimitOrderTranche at tick $19640$. Since this is a limit order, when swapped through and depleted the liquidity is removed from state and the USDC Alice paid is credited to the limit order Receiver

2. Alice swaps up to $71.428$ USDC using this pool before depleting the reserves. This will net her $10$ ATOM for the swap:

   $\text{ATOM available} / \text{exchange rate} = \text{USDC needed}$ $10 / 0.14 = 71.428$

3. Alice still has $28.527$ USDC she needs to swap, so we move to the next available tick: $-20795$ This tick offers ATOM at a price of $0.123$ ATOM per USDC and is of type PoolReserve. Any USDC Alice pays for this swap will be placed in the corresponding poolReserves of the Pool (USDC @ Tick $-20795$ .) Alice swaps the remainder of her USDC here, resulting in an additional $3.5$ ATOM:

   $\text{USDC in} * \text{exchange rate} = \text{ATOM out}$ $28.527 * 0.123 = 3.5$

4. Done. Alice has swapped $100$ USDC for $13.5$ ATOM with an average price of $0.135$ ATOM per USDC.

NOTE: For the clarity of this example we are assuming that the PoolReserves have a fee of zero. In a real world scenario almost all PoolReserves will have a fee. In a scenario with fees TokenIn will be added to $Tick * -1 + (2\cdot fee$). Learn more about fees in the PoolReserves section.

Example liquidity Placement Post Swap

We are still displaying the tick liquidity at $19640$ as a visual aid. In reality this tick is depleted and removed

There are different behaviors a taker limit order can take when swapping. for example, here we were not sensitive to Price. Learn more about the order types and their unique behaviors in the Order Types section.