US Equities ASID Lookup

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. ASID vs SecId: SecId stays unchanged through name and ticker changes but may change on certain restructurings (guide example: reclassification). ASID is the higher-level identifier that stays constant for the whole life of the security and links all its SecIds, letting you build uninterrupted price/reference history. SecIds and SecIdsStartToEndDate are chronological and positionally aligned; e.g. ASID 1010000000001003 (ticker AAA) = SecIds 6561562 (20200909:20221014) then 7680133 (20221017:29991231). Boundaries fall on consecutive trading days and end dates read as inclusive. Tickers are aggregated across the whole SecId chain (e.g. YHOO;AABA for ASID 1010000000001006), so ticker history here can be longer than for any single SecId in the ticker Lookup File. A ticker can recur under different ASIDs: AAA 20070103:20070521 (SecId 78768) is ASID 1010000000001002, while the later AAA (SecIds 6561562, 7680133) is ASID 1010000000001003 - a ticker is not a security key.

Coverage

All listed and delisted US equity securities (stocks, ETFs, ETNs, ADRs, preferred stock, warrants and similar) from 2007 to present, with ticker changes and their date ranges. Complementary dataset for securities whose SecId changed.

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 (6)

• Primary key is inferred; AlgoSeek's guide does not name one.
• Documentation discrepancyHeader vs guide: sample header (and JSON keys) use TickersStartToEndDates (plural); both the ASID guide and the Security Master guide's Table 10 spell it TickersStartToEndDate.
• Documentation discrepancyASID type: this guide (Table 2) says integer, but the Security Master and Lookup Files guide (Table 10, v1.7 Oct 2023) says string; sample values are 16-digit numerics. Decision rule: treat as an opaque identifier; it fits a signed 64-bit integer.
• Documentation discrepancyGuide Table 2 typo 'tricker1;ticker2'; Security Master guide Table 10 capitalises String for SecIds. Cosmetic only.
• Documentation discrepancySame dataset is documented in two guides (this one, v1.1 Jun 2023, and Tables 9-10 of the Security Master/Lookup guide v1.7 Oct 2023); the field tables agree except for the ASID type and the header plural noted above.
• Documentation discrepancyGuide has no Missing/null column beyond 'Never' for every field; sample has no blanks.