US Equities Trading Halts

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. Identifiers: SecId and ASID are both algoseek keys 'added for cross-referencing with other US equity datasets'; both can be empty (e.g. test symbols such as ZWZZT/ZVZZT; FCHL, FFFZ, RNBW also lack ids in sample). Symbol is always present but is a ticker, not a stable key. ASID prefix 101 is for listed equities (OTC security master ASIDs start 121 in its sample). Date semantics: Date is the processing/file date. A halt that persists is repeated in later dates' files with its original HaltDate (sample Date 20250814 carries HaltDate 20250715 rows with EodStatus Halted); a halt that began earlier and resumed on Date also appears (ResumeDate = Date in every resumed sample row). Do not treat Date as the halt start; use HaltDate + HaltTime*. Time semantics: HaltTime* reflect dissemination of the halt notice, not necessarily the instant trading stopped. Each time exists in an Exch (exchange-stamped) and a Sip (SIP-stamped) version, both with nanosecond digits; in the sample SIP time is 14-614 microseconds after the exchange time, except one long-running halt (SVA, HaltDate 20241025) whose HaltTimeSip is about 52 minutes after HaltTimeExch. Time zone is not stated; times are bare clock strings without date, so combine with HaltDate/R… Open halts: a halt may outlast the session; then ResumeDate, UtpQuoteResumeTime*, TradeResumeTime* stay blank and EodStatus = Halted (17 of 60 sample rows). EodStatus = Trading implies ResumeDate is set (43 of 60).

Coverage

Halts across all US equity exchanges, derived from the CTA feed (NYSE, NYSE American and other listed securities) and UTP feed (Nasdaq-listed and UTP-eligible securities). History start is not stated in the guide.

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 (8)

• Primary key is inferred; AlgoSeek's guide does not name one.
• Documentation discrepancyHeader spelling differs between guide and sample: the guide Table 2 lists HaltTimeSIP and TradeResumeTimeSIP, the published CSV header uses HaltTimeSip and TradeResumeTimeSip (UtpQuoteResumeTimeSip matches in both).
• Documentation discrepancyGuide types HaltCaseSeq as string, but every sample value is a small integer (1-5); guide types TotalMessages as integer.
• Documentation discrepancyGuide AsNormRsn text for code D is 'News Released' (Tables 3 and 4), but sample rows with D carry the longer 'News Released (formerly News Dissemination)'.
• Documentation discrepancyGuide Table 4 describes the Level 2 circuit-breaker resumption as 'if previously level 3' (apparent typo for level 2) and spells 'Filling Requirements' for 'Filing Requirements'.
• Documentation discrepancyGuide Table 1 sample for the CTA row (ACCS) shows a time under UtpQuoteResumeTimeSip, which the field definition limits to UTP-plan securities; the published CSV has that CTA value in TradeResumeTimeExch and leaves UtpQuoteResumeTime* blank, so the guide example is likely mis-aligned (possibly a layout artifact).
• Documentation discrepancyGuide gives no Missing column; blank behavior is only described in prose (special cases section) and the SecId/ASID field text.
• Documentation discrepancyGuide says both SecId and ASID are 'algoseek unique security identifier' with identical text; the two are distinct values (SecId 7-8 digits, ASID 16 digits starting 101 in sample) and the guide does not explain the difference.