Provider definitions, coverage, timestamps, aggregation, missing values, and conflict resolution.
By the end, you should be able to
- Ask who measured a value and how.
- Interpret missing, stale, and conflicting data.
- Document a reproducible source check.
Two market caps can both follow their methods
Illustrative provider differences often begin with supply estimates.
A metric is a method plus a value
Before using a number, record provider, endpoint or page, definition, units, venue coverage, timestamp, and transformation. Two reputable providers can differ because they measure different samples.
Unavailable is not zero
A missing value may reflect unsupported assets, rate limits, delayed indexing, provider policy, or a request error. Treating missing data as zero creates false precision.
Resolve conflict without forcing agreement
Check identifiers, quote currencies, time zones, update times, supply definitions, and included venues. If differences remain, report the range and methodology instead of selecting the preferred answer.
What this does not tell you
- A precise timestamp does not guarantee the underlying source is current.
- Aggregators inherit exchange and project-reporting limitations.
- More providers do not automatically produce a more accurate consensus.
Run a two-source check
Compare a metric while preserving the reason for any difference.
- Choose one asset and one metric.
- Record values, timestamps, units, and definitions from two sources.
- Explain the difference or label it unresolved.
Check your understanding
1. What should accompany a data value?
2. What should missing data mean?
3. How should unresolved provider differences be reported?