Point-in-time correctness
The property that a dataset reflects only information genuinely available at each historical timestamp — including the values as first reported, before restatement, and the constituent sets as they stood, before survivorship filtering.
The position
This is the single fault line between a backtest and a story, and it is almost never the headline feature a data vendor sells on. Latency is marketed; point-in-time integrity is buried in documentation, because it is expensive to maintain and invisible until someone tries to reproduce a result. When evaluating any market data provider, the question that separates them is not how fast the feed is — it is whether restatements are preserved as a versioned history or silently overwritten.
This section is a claim, not a definition. It is argued rather than asserted, and it is the part of this page you are invited to disagree with. Corrections and counter-arguments to [email protected] are published.