Start with identity, units and time

Check the asset’s name and type, its currency and, for an exchange listing, its market. A similar symbol does not establish the same instrument. Distinguish the observation’s source time from the time you loaded the page: reopening an older quote does not create a new trade.

Read a curve and a percentage in context

Compare matching periods and check whether the chart contains dated points, completed daily closes or only source ordering. These views have different meanings. A price change does not automatically include dividends, staking rewards, currency conversion or the costs of a particular investor.

A dash marks an unavailable value rather than zero. During a source outage, read the stated status and the timestamp of any last-known observation. Missing history cannot establish a stable price, and a movement alone does not prove its cause.