# Fee Tiers

Every pair on Biscotti can have up to three concentrated-liquidity pools — one
per fee tier. Each tier is a separate pool with its own liquidity, price and
tick spacing.

## Available tiers

| Fee tier | Fee (`uint24`) | Tick spacing | Best suited for |
| --- | --- | --- | --- |
| **0.05%** | `500` | 10 | Like-priced & low-volatility pairs (e.g. USDC/EURC) |
| **0.30%** | `3000` | 60 | Most volatile pairs (e.g. BSCT/USDC) |
| **1.00%** | `10000` | 200 | Exotic / long-tail assets |

The fee parameter is expressed in hundredths of a basis point
(`500 = 0.05%`). Tick spacing constrains where positions may start and end —
see [Ticks & Price Ranges](/concentrated-liquidity/ticks-and-ranges).

## How fees flow

On every swap, the fee is deducted from the input amount and credited to
`feeGrowthGlobal` for the pool. Only positions **in range at the moment of the
swap** accrue a share, proportional to their fraction of active liquidity.
Fees accumulate inside the position and are paid out when you call `collect`
on the `NonfungiblePositionManager` — they do **not** auto-compound.

## Choosing a tier as an LP

* **Match the pair's volatility.** Stable pairs can't justify a 0.30% fee —
  traders will route elsewhere; volatile pairs at 0.05% underprice the
  impermanent-loss risk you carry.
* **Follow the liquidity.** The [Smart Router](/smart-router) routes to
  whichever tier gives traders the best all-in price. A tier with deep
  liquidity attracts the volume — and the fees.
* **Check Analytics.** [Info pages](/analytics) show per-pool volume and TVL
  so you can compare realized fee APR across tiers of the same pair.

:::tip[Same pair, multiple tiers]
It's normal for one pair to have active pools at several tiers. Arbitrage
keeps their prices aligned, and the router splits trades across them when
that improves execution.
:::

## Creating a pool at a new tier

Anyone can create a pool for any pair/tier via the factory:

```solidity
UniswapV3Factory.createPool(tokenA, tokenB, fee)
```

or implicitly through the position manager's
`createAndInitializePoolIfNecessary` when minting the first position. See
[Managing Positions](/concentrated-liquidity/managing-positions).