US Equities Basic Shares Outstanding

How to use it

Rows are effective-dated. Answer point-in-time questions with the row in force on the as-of date, never the latest row. SecId and ASID are both durable AlgoSeek security keys but different values (the ASID lookup links them); tickers are reused across companies, so resolve a ticker to a key with a trade date.

Typical use

Point-in-time security identity, corporate-action adjustment, and universe construction for US equities.

Limitations

Vendor-curated reference data: rows can be restated when AlgoSeek learns of a late or corrected event, so land each delivery as a snapshot rather than overwriting history. Three dates, as-of semantics: EffectiveDate = effective date of the SO value change (the as-of date of the figure); CreatedDate = trading date on which algoseek created the SO event; ChangedDate = date (optionally with an _n version suffix) on which the event was last changed. In the samples CreatedDate is never earlier than EffectiveDate (gap 1-93 days), so CreatedDate (or ChangedDate if revised) is the date a figure could have been known - use it, not EffectiveDate, to avoid look-ahead (infer… Event/step data, not a daily series: a row is a new SO figure. SO on a date D is the SharesOutstanding of the latest row with EffectiveDate <= D (and CreatedDate <= D for point-in-time use); it persists until the next row (inferred from the 'event' wording). SharesOutstanding is 'the new shares outstanding figure' (a level, not a change) captured from stock exchanges and company websites as soon as the official source publishes it; official update frequency varies from daily to annual, so gaps of months or years between rows are normal. Values are as reported, not restated for later splits (inferred from samples): AAPL 861,874,894 effective 20070124 versus 16,687,631,000 effective 20210416 (guide Table 1), and ARCI drops from 8,472,651 (effective 20181229) to 1,694,530 (effective 20190422), about one fifth, consistent with a reverse split. Recent figures are often rounded to thousands (ending in 000). Combine with the Adjustment Factors datasets if a split-consistent share count is needed.

Coverage

US exchange-listed equity securities from 2007 to present (product page); official shares-outstanding figures from exchanges and company websites. Sample has three SecIds (AAPL 82 rows to 20230721, APPB 4, ARCI 23).

Usage constraints

• Licensed vendor data: never export raw rows to a tenant-local destination or include them verbatim in a public artifact; serve only through entitlement-checked platform reads.
• Do not treat the vendor's `Ticker` as a stable identity across time; join on an AlgoSeek security key (SecId or ASID, which are distinct) or the platform symbol mapping.

Known issues (7)

• Primary key is inferred; AlgoSeek's guide does not name one.
• Documentation discrepancyGuide Table 2 documents CreatedDate as a 'trading date', but 17 of 109 sample rows have a Saturday CreatedDate (e.g. 20071117, 20171104, 20200104, 20230805); in 11 rows ChangedDate is the following Monday.
• Documentation discrepancyChangedDate is documented as yyyymmdd[_n] with a version suffix, but none of the 109 sample rows carries a suffix.
• Documentation discrepancyUpdate cadence: guide says 'a couple of times a day' (starting 04:00 AM EST); product page says 'multiple times per day'.
• Documentation discrepancyFile names: guide mentions so_basic.csv / so_detailed.csv; published samples are eq_shares_outst_basic.csv / eq_shares_outst_detail.csv.
• Documentation discrepancyGuide gives no Missing/null column for this dataset; the sample has no blank values.
• Documentation discrepancyNo unique key is stated for the Basic file (no EventId column); (SecId, EffectiveDate) is unique in the 109-row sample, but the guide says events can be 'changed', so revisions may repeat an effective date.