How old can a liquidity snapshot be before it becomes misleading?

There is no universal number of seconds after which every liquidity snapshot becomes unusable. Its relevance depends on what changed after the observation and how sensitive the intended trade is to that change.

Identify state-changing events

Trades can move the starting price and reserve composition. Deposits and withdrawals can change depth. Concentrated positions can become active or inactive as price moves. A snapshot taken moments earlier can therefore be less useful than an older snapshot from an unchanged pool.

Reserve changes affect execution price. Freshness is about state correspondence, not the age label alone.

Match the snapshot to the quote

Record the observation time and block or other state identifier where available. If a chart uses delayed indexed data while the quote uses current execution state, do not expect them to reconcile exactly.

For a hypothetical large trade near a thin range boundary, a small starting-price movement can change which liquidity is traversed. A smaller trade well inside a dense range may be less sensitive, although its quote still needs validation.

Use a practical acceptance rule

For current execution, obtain a current size-specific quote and inspect the required constraints. For historical analysis, use the snapshot corresponding to the historical observation rather than substituting today's distribution.

If the relevant state is unavailable, label the depth analysis approximate. Do not claim a failed transaction contradicts an earlier chart unless you have established that the pool, size, direction, fees and execution state matched.

Repeatedly updating a chart is helpful only if the underlying data updates too. A fresh page-load timestamp does not prove fresh pool data. Preserve the data timestamp when provided, and distinguish it from the time you opened the interface. That distinction makes liquidity claims easier to reproduce and prevents stale indexed information from being presented as an executable offer.