Depth is a stock: capital sitting in the pool, available to trade against right now. Volume is a flow: value that changed hands over some window. They are measured in the same units, printed next to each other, and answer entirely different questions.
The two ways they come apart
High volume, thin depth. Common on a newly launched token: heavy turnover recycling through a small reserve. The volume figure looks like a liquid market and the pool cannot absorb a serious order without severe price impact. Volume here is a measure of activity, and activity is not capacity.
Deep pool, low volume. Less exciting and often the better structure. Capital is committed, nobody is churning it, and a real order can be filled without moving the price much. A ranking by volume will bury this token beneath something far more fragile.
Why volume is the more corruptible number
Depth has to be posted. To make a pool look deep you must actually put capital in it and leave it there, exposed to impermanent loss and to anyone trading against you. It is expensive to fake and the cost is continuous.
Volume requires no such commitment. The same capital can be traded back and forth against itself indefinitely, generating an arbitrarily large figure at a cost of fees alone. That does not mean a high-volume token is manufactured — most are not — but between the two numbers, the one that is expensive to fake deserves more of your trust.
The ranking trap
Both metrics share a defect worth stating once more: sort a chain’s pools by either and the top of the list is the gas asset paired against the chain’s dollar. Those pools exist so other trades can route through them, so they are simultaneously the deepest and the busiest, for reasons that have nothing to do with anyone wanting to own either asset. That is covered fully in routing pools versus real demand.
Which to use
Use depth to decide your size, and specifically the depth you will be exiting into rather than entering against. Use volume to judge whether anyone is there — a deep pool nobody trades is a token you may own for a long time. Neither alone answers the question that matters; both together are close to a complete read.
The NoVo Crypto Market Map reports depth, turnover and cost to move as three separate figures for that reason. Collapsing them into one “liquidity” score would throw away exactly the disagreement that carries the information.