# How Market Backstory measures market history

The definitions behind endpoint changes, drawdowns, recoveries, matching conditions and complete annual windows.

## Prices, dates and common intervals

An endpoint change uses two retained levels and their exact dates. Comparisons use eligible common observations. There is no forward fill of an absent close and no claim that a capture proves exchange-calendar completeness.

Fund data are provider-adjusted records; selected company studies preserve their separately stated price basis. No single-security sample is described as an official market index or a representative population.

## Drawdown and recovery

An interval drawdown uses the highest eligible close since the selected start. Recovery is the first later observed close at or above the corresponding episode peak. Unrecovered cases remain unfinished in the retained record.

Calendar durations are elapsed calendar days. Forward Lab horizons count retained subsequent observations. These units are not substituted for one another.

## Historical-condition studies

History Lab first identifies eligible observations and contiguous matching stretches. It then reveals the subsequent paths when the reader asks. Edited controls do not silently rewrite the last submitted result.

Forward paths start at the selected anchor. Full-horizon summaries exclude incomplete cases while charts retain partial paths. Required missing inputs are reported as exclusions; optional context does not manufacture matches.

## Annual research and selection limits

Annual research compounds consecutive source-year factors. Missing periods remain missing. Native units, currency, source country and return field remain visible. Dividends and reinvestment are not inferred from an unlabeled series.

The catalogue contains selected surviving instruments and authored retrospective cases. It does not establish historical index membership, failed-company wealth, point-in-time valuation expectations or what an investor knew at the time.

## Revisions and corrections

This launch serves retained captures, not live market quotes. Observation date, retrieval date and editorial revision are separate. A newer provider vintage can revise history without changing the original observation label.

Send the page URL, selected interval, figure basis and the discrepancy to contact@marketbackstory.com. We distinguish a data correction from an interpretation and identify material changes when publishing them.

## Related research

- [Find a figure and inspect its evidence](/contents/)
- [Credits and licences](/credits.html)
- [Contact and corrections](/contact/)