Definitions
In plain terms
The universe answers which securities were actually eligible on that date, without adding later listings or removing securities only because their later history is now known.
Technical
A point-in-time issue universe is a versioned roster produced under a stable membership methodology, session calendar, identity scheme, and causal information cutoff for one venue or feed scope.
Scope
This pilot definition governs reproducible breadth inputs; it does not claim that a free aggregate market-summary file exposes a complete historical member roster.
Examples
- A 2024 breadth calculation uses the issues eligible in 2024, not today's surviving listings.
Common misconceptions
- A current security list cannot automatically reconstruct a historical point-in-time universe.
Concept relationships
Where this concept is used
- ImportantHistorical Constituent Reconstruction: Rebuild the Roster Without Looking AheadD02-F04-A01
- PrerequisiteSurvivorship-Bias Guard: Keep Historical Failures in the TestD02-F04-A02
- PrerequisiteNet Advances: Count Participation Without Hiding Data GapsD04-F01-A01
- PrerequisiteAdvance/Decline Ratio: Advancing Issues per Declining IssueD04-F01-A02
- ImportantNormalized Advance/Decline Line: Cumulative (A-D)/(A+D) BreadthD04-F01-A04
- ImportantAbsolute Breadth IndexD04-F01-A05
- ImportantSector Diffusion IndexD04-F05-A04
Evidence and governance
- Daily Market Summary Data Fields and Definitions Nasdaq, Inc. · official exchange
Supports: short definition, technical definition, units
Limits: Does not define the pilot's exhaustive partition, causal cutoff, revision lineage, EMA policy, or normalized breadth formula.
- Reviewed by
- fintech-builder-owner-approved
- Last reviewed
- 2026-07-26
- Next review
- 2027-07-26
- Record status
- published