Self-Reported Supply Figures
Circulating supply is often a number supplied by the project, computed under rules that differ between data providers and can change without notice.
How it happens
Market capitalization requires a supply figure, and there is no standard defining which units count. Providers must decide how to treat foundation holdings, unvested allocations, tokens burned to an address nobody controls, staked balances, bridged representations that exist simultaneously on several chains, and units held by the issuer for future sale. Projects often supply the figure themselves, and providers apply their own adjustments on top with varying transparency. Because rankings and index inclusion depend on the result, the incentive runs toward the interpretation that produces a larger number. Unlike a share count in an audited filing, circulating supply has no legal definition, no auditor, and no filing deadline, so two reputable sources can publish different figures for the same asset on the same day.
What you can actually observe
Reconstruct supply from the token contract itself, subtracting balances in vesting contracts, identified treasury addresses, and burn addresses, then compare that with the provider's published figure. Read the provider's methodology document and its revision history, and check whether bridged or wrapped versions are double counted. Where a project publishes its own supply dashboard, compare it with the on-chain reconstruction rather than accepting it.
What makes it more or less material
Check the gap between reported and on-chain reconstructed supply, whether the figure is project-supplied, how much sits in treasury and vesting contracts, and whether bridged copies are counted more than once.