Zero, null, unavailable, stale and unsupported

Significado en lenguaje sencillo

Zero, null, unavailable, stale and unsupported means examining the provenance, timestamps, identity, units, missingness and reproducibility of every market or research observation with the identity, period, unit, source and limitations kept visible. It is a disciplined way to describe evidence, not a shortcut to an investment conclusion.

Learning objectives #

After this chapter you should be able to define zero, null, unavailable, stale and unsupported, identify the evidence needed to use it, distinguish a reported zero from unavailable evidence, and explain why unlike instruments or periods may not be comparable.

Prerequisites #

Read “As-of, retrieval and generated timestamps” first. Be comfortable checking an exact listing or instrument, its source, observation date, native currency and unit. When any one of those is unknown, pause the comparison and record the gap.

Core concept #

Zero is evidence; null/unavailable encode absent computation, while stale and unsupported explain why. Preserve raw facts separately from interpretation, and retain the denominator, time window, classification rule and provenance that make the evidence reproducible.

Method #

For zero, null, unavailable, stale and unsupported, first identify the exact evidence named in this chapter: Zero is evidence; null/unavailable encode absent computation, while stale and unsupported explain why. Then freeze identity and period, collect source-backed inputs with units, calculate or classify only compatible evidence, and record contrary facts and unavailable fields.

Where it appears in XMarketRadar #

Source, retrieved-at, as-of and unavailable labels appear across XMarketRadar. The Help catalogue itself is checked-in editorial data and has no live dependency. A displayed field is useful only with its source and as-of context. If XMarketRadar does not calculate this chapter’s concept directly, use the chapter as an educational checklist and retain the supporting primary document or screen URL in the research workspace.

Worked example #

Published dividend 0 is zero; missing dividend feed is —; Friday close 100 shown Monday is stale 100. Module context: Illustrative verified close is CU 100 at 16:00 on 3-Aug-2026, retrieved 16:08; a failed 4-Aug fetch retains CU 100 labelled 3-Aug stale or shows —, never a fabricated CU 101. This is an illustrative audit trail, not live data, a target or an expected outcome.

Interpretation #

Interpret the result in the direction defined by the field, not by an assumed desirable outcome. Higher, lower, positive and negative can each have different meanings by context. Compare the observation with its own history or a compatible benchmark, and label conclusions as observations, interpretations or user decisions.

Limitations and common mistakes #

Coercing null to 0 or hiding stale labels. Providers can revise history, disagree on adjustments, return duplicate dates, omit fields or use timestamps that represent retrieval rather than observation. A precise calculation can still mislead when the source is stale, the denominator changed, or a classification hides important detail.

Unavailable evidence #

If evidence needed for this chapter’s focus is missing—Zero is evidence; null/unavailable encode absent computation, while stale and unsupported explain why.—the result is unavailable (—). Do not resolve the gap by coercing null to 0 or hiding stale labels. It is not zero, neutral, low risk, a failed condition or permission to substitute a different listing. Retain the last verified observation only with its original date and stale label.

Market and jurisdiction differences #

Sessions, holidays, symbol systems, licensed fields, decimal scales and corporate-action sources vary. An empty international universe never falls back to another exchange. Exchange rules, accounting conventions, calendars, taxes, disclosure timing, quote scale and licensed coverage can differ. Verify the current primary source for the relevant venue; registry support alone does not prove that every field is available.

Key takeaways #

For zero, null, unavailable, stale and unsupported, remember this boundary: Coercing null to 0 or hiding stale labels. Keep the evidence exact, dated and source-backed; publish missing information as unavailable rather than manufacturing a value.

Practice #

Reproduce this historical scenario from source-labelled inputs: Published dividend 0 is zero; missing dividend feed is —; Friday close 100 shown Monday is stale 100. Then change one input, preserve the original period and unit, and explain whether the result changes or becomes unavailable. Write the identity, source, date, unit and failure condition, then state exactly what would display as —.

Knowledge check #

Related next steps #

Continue with “Exchange identity and symbol collisions”. Follow the previous/next chapter links and related glossary terms for canonical definitions. Re-run the checklist whenever the source, period, instrument identity or methodology changes.

Educational use only #

This chapter is descriptive education, not investment advice, a forecast, a recommendation, a suitability assessment or an instruction to buy, sell, rebalance, trade or place an order. XMarketRadar’s broker connections remain read-only.