Full-range AMMs: how liquidity shapes a swap

A full-range AMM makes liquidity available across a wide span of prices, so a swap can keep trading as the pool’s price moves. In a constant-product pool, the reserves of the two assets follow the rule x × y = k: the more of one asset a trader removes, the more the price changes against that trade.

That broad availability is useful to swappers because liquidity is not confined to a narrow price band. It does not mean every trade gets the same price, or that every pool has enough depth to handle a large order cheaply. For a closer look at how pool design affects trade execution, blackhole swap explains a related mechanism in more detail.

How does full-range liquidity affect a swap?

Full-range liquidity supports trading across prices rather than concentrating all of a provider’s capital around one chosen price. In an AMM using the constant-product rule, a swap adds one asset to the pool and removes the other. The reserve ratio changes, and that change sets the new price. Larger trades generally move the ratio further, so they incur more price impact.

Price impact is the change caused by the trade itself. Slippage is the difference between the expected execution price and the price actually received, which can also reflect price movement while a transaction waits to execute. A pool’s total value locked alone does not show how much liquidity is available along the specific price path the swap will take.

How do concentrated pools change the mechanics?

Concentrated-liquidity pools let providers allocate liquidity within selected price bounds. Within those bounds, the position can act like a pool with larger virtual reserves, supporting trades with less price impact for a given amount of capital. Uniswap v3 introduced this model; Uniswap v2 distributes liquidity across the full price interval.

When a swap moves the price through a concentrated position’s range, that position’s liquidity helps serve the trade. At a boundary, the position becomes inactive and stops earning fees until the price returns to its range. As price approaches either bound, the position’s assets shift toward one token; outside the range, it holds only that token. Other positions in the pool may still be active.

This creates a trade-off for swappers. Concentration can make a price band deeper, but execution depends on how much liquidity is active at the current price and along the route the trade follows. A pool with large total liquidity can still have little available near the market price.

What should a swapper check before trading?

Compare the quoted output and price impact for the same trade size, then check the route and the pool’s active liquidity. A practical check is to compare:

• Trade size: A larger order can move the pool price further.
• Active liquidity: Concentrated liquidity outside its bounds does not serve the current trade.
• Route: A swap may pass through more than one pool, each with its own price impact and fee.
• Minimum output: The transaction’s slippage limit determines how much less than the quoted amount you will accept before it reverts.

For routine swaps, the useful comparison is the executable quote for your trade, not the pool’s headline size. Full-range liquidity offers broader price coverage; concentrated liquidity can offer deeper trading near the current price, provided that price remains within the active ranges.