Liquidity

In practice, liquidity is measured by looking beneath the surface of a market rather than at price alone. Traders watch the bid-ask spread, the gap between the highest buy offer and the lowest sell offer, along with the volume of orders resting near the current price. A tight spread backed by deep resting orders signals a liquid market; a wide spread with thin orders signals the opposite, even if the asset trades on a well-known exchange.

On centralized exchanges, this depth comes from an order book where buyers and sellers post limit orders, often kept tight by professional market makers. Decentralized exchanges take a different approach: instead of matching individual orders, a DEX typically relies on an automated market maker, where users called liquidity providers deposit paired tokens into a shared pool and a formula sets the exchange rate based on the pool's balance. In both models, more liquidity means large trades execute closer to the quoted price.

Liquidity matters because it directly affects trading costs and risk. In a thin market, a single large order can move the price sharply, a problem known as slippage, and can make it hard to exit a position without accepting a worse price. Liquidity should not be confused with trading volume: volume counts how much changed hands over a period, while liquidity reflects how much is available to trade right now. A coin can show a volume spike from a short burst of activity yet remain thinly traded once that burst passes, so both metrics are best read together, along with market capitalization, when judging how easily an asset can be bought or sold.