US Equities Basic Adjustment Factors

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. AdjustmentFactor is a multiplicative per-event ratio. Backward adjustment (anchored on the latest date): a price dated D is multiplied by the product of the AdjustmentFactor of every event whose EffectiveDate is later than D; prices on or after the latest EffectiveDate use AF=1. An event therefore changes only dates strictly before its EffectiveDate. Guide worked example (formulas are images in the PDF), AAPL 2014 with f1=0.995050548 (20140807 CashDiv), f2=0.142857143 (20140609 BonusSame), f3=0.994445664 (20140508 CashDiv): prices from 20140807 use AF=1; 20140609-20140806 use f1 (0.99505); 20140508-20140608 use f1*f2 (0.14215); earlier dates use f1*f2*f3 (0.14136). Volume is DIVIDED by the corresponding cumulative factor, and only events with Affects Volume = Yes enter that product (BonusSame, CapReduct, Cons, ScriptDiv, SecSwap, Reclass, Subdiv). In the guide example only the 20140609 BonusSame touches volume, so volumes before 20140609 are divided by 0.142857143 (x7) and later volumes by 1. Price-only reasons (CashDiv, Distrib, DeMerg, rights, etc.) must not be applied to volume. Forward adjustment is said to be possible ('forward- or backward-adjusted pricing') but this guide only walks through the backward procedure; the Cumulative Adjustment Factors dataset publishes ready-made forward factors.

Coverage

All US exchange-listed equities (stocks, ETFs, ETNs, ADRs, preferred stock, warrants and similar), events from 2007 to present. Sample is AAPL only (32 events, 20120809-20200207).

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)

• Update cadence and publication latency are not stated in the guide; confirm with AlgoSeek (or GET /v1/meta/datasets/{id}/status).
• Documentation discrepancyGuide text says the CSV rows correspond to 'individual bars' (boilerplate copied from price guides); rows are corporate-event records.
• Documentation discrepancyGuide's reason table is grouped by Event Type, but the Basic field table and sample header have no EventType column (it exists only in Detailed/Cumulative/Daily Cumulative datasets).
• Documentation discrepancyGuide Table 1 prints AdjustmentFactor rounded to 10 digits (0.9944456637, 0.1428571429) and Table 4 to 9 digits; sample delivers 15-16 significant digits (0.994445663734742, 0.142857142857143).
• Documentation discrepancytradedate aggregation wording is ambiguous: 'one CSV file with data per symbol per effective date' versus the example of all events on one date in a separate file.
• Documentation discrepancySample is a 32-row AAPL extract ending 20200207: it contains only CashDiv (31) and BonusSame (1) and omits AAPL's 20200831 Subdiv that appears in the Cumulative dataset sample, so it is truncated, not a complete history.
• Documentation discrepancyGuide FAQ concedes that two dividends on the same date for one ticker cannot be told apart in Basic (they differ by dividend period only in the Detailed Detail column).