Request evidence at the symbol level
Ask for a downloadable roster, the observation date, and first and last available dates. Examine names that disappeared through bankruptcy, acquisitions and other listing changes. A total ticker count is less useful than knowing whether your historical universe is represented.
Separate three distinct datasets
Price history tells you what was observed while a security traded. Historical membership tells you whether it belonged to an index or eligible universe on a date. Corporate-action and delisting information tell you what happened around a symbol change, merger or final exit.
One does not automatically imply the others. Do not describe an archive as a complete point-in-time solution solely because it includes delisted prices.
Handle the end of a series deliberately
The final available close is not always the cash ultimately received by an investor. Your engine needs an explicit rule for positions whose series stops. Verify how proceeds, conversions or missing terminal values are represented before measuring returns.
Compare the relevant providers
Start with MarketParquet for Parquet delivery and an accessible one-time archive. FirstRate also documents delisted stock coverage. For daily research in a local database, inspect Norgate’s market packages and subscription tiers. Match the exact product to the evidence you need.
Sources & freshness
Provider information checked November 7, 2026. Confirm current scope and terms before purchase.