US Equities Security Master File

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. Identifier hierarchy: SecId is algoseek's own key - stable across ticker/name changes but it can change after a restructuring such as a reclassification; ASID (see US Equities ASID Lookup) is the higher-level key that chains SecIds for one security's economic life. Ticker is not a key: the same ticker can belong to different SecIds in different periods (guide example: S for Sprint Nextel, later Sprint), and ticker changes keep the SecId. Resolve Ticker+date to SecId through the Lookup File, not from this table alone. Cross-reference columns: ISIN (12-char, list), USIdentifier (9-char CUSIP-style, list), FIGI (12-char, list), SEDOL (deprecated, current only). SecId->ISIN/US identifier/FIGI is one-to-many over time; ISIN and USIdentifier carry their own date lists, FIGI does not. FIGI choice: algoseek uses the Primary Exchange Composite FIGI when available, otherwise the plain FIGI; some entries are blank when no FIGI matches a period. Guide best practice: use the LAST FIGI listed as the reference id.

Coverage

All listed and delisted US equity securities (stocks, ETFs, ETNs, ADRs, warrants, preferred stock and similar) from 2007 to present. Page says it is a single consolidated table updated daily for new listings, delistings and reference-data changes. A separate Lookup File dataset resolves ticker/FIGI/ASID to SecId.

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 discrepancySic: guide types it integer (Table 2 shows e.g. 3350, 3571) but every sample row serializes it as float-style text ('3571.0', '5812.0').
• Documentation discrepancyUSIdentifier: guide Table 1 shows AAPL as 037833100 (9 chars); sample/JSON delivers 37833100 - leading zeros stripped when the code looks numeric (of 129 sample entries, 79 are 9 chars incl. the 2 corrupted ones below, 48 are 8 chars, 2 are 7 chars).
• Documentation discrepancyUSIdentifier for SecId 33551 and 33619 is spreadsheet-corrupted in both sample CSV and JSON preview ('4,27E+110' and '4,62E+211', i.e. scientific-notation mangling of 04269E107 and 04622E208); do not treat as valid codes.
• Documentation discrepancyGuide never names the 'USIdentifier' type; values and the ISIN embedding (US ISIN = 'US' + 9-char code + check digit) match CUSIP format, so CUSIP is inferred, not documented. The word CUSIP does not appear in the guide.
• Documentation discrepancyGuide describes FIGI as a list with no StartToEndDate column; in all 100 sample rows the FIGI entry count equals the ISIN and USIdentifier entry counts, so FIGI appears positionally aligned to ISIN/USIdentifier periods (inferred, not stated).
• Documentation discrepancyGuide says the file is named equity_security_master.csv; published sample file is eq_sec_master.csv (naming of the sample differs from the delivered file name).