Volume is not liquidity
Trading volume measures completed activity over a period, while liquidity describes the ability to trade when needed without moving the price sharply. A large volume figure can still be concentrated among a few accounts or one venue, and reported activity does not necessarily equal the depth available for a new order.
Quotes and spreads
The gap between the best bid and best ask is the spread. A wide spread increases the difference between a displayed midpoint and an executable price. Review the quantity available across several price levels rather than looking only at the nearest quote.
Depth and price impact
A larger market order can consume several levels of the order book and produce a worse average price. This price impact or slippage is part of the transaction cost. Estimating how much your own order changes the price is more useful than relying only on an expected return.
Liquidity differs by venue
The same asset can have different prices, depth, and withdrawal conditions across exchanges. Aggregate volume does not guarantee liquidity on the venue you use. Fiat pairs, stablecoin pairs, spot markets, and derivatives should also be treated as different structures.
Liquidity under stress
Liquidity visible in normal conditions can disappear during a sharp move or operational failure. Market makers may withdraw quotes and an exchange may suspend deposits or withdrawals, allowing price differences to widen quickly. Review past stress periods and the venue’s operational history.
A practical checklist
Check the spread, order-book depth, estimated slippage, venue concentration, and withdrawal status before trading. Understand the trade-off between market and limit orders and consider splitting a large order. Liquidity is an execution risk that exists separately from your view of future price.