---
title: "US Equities Basic Adjustment Factors"
method: GET
path: "/v1/data/us-equity-ref/adj-factors-basic"
tags: ["us-equity-ref-corporate-actions"]
---

# US Equities Basic Adjustment Factors

`GET /v1/data/us-equity-ref/adj-factors-basic`

The U.S. Equities Basic Adjustment Factors dataset provides adjustment factors that affect price, volume or both for corporate events that impact historical equity time series. Each adjustment entry is accompanied by the adjustment reason, enabling transparent and reproducible application of corporate-action adjustments. The dataset allows users to compute both forward- and backward-adjusted price and volume series, supporting a wide range of analytical and back-testing methodologies. Coverage includes all U.S. exchange-listed equities, with historical data available from 2007 onward.

 For more details, please refer to the dataset documentation: [US Equities Basic Adjustment Factors Guide](https://us-equity-reference-docs.s3.us-east-1.amazonaws.com/algoseek.US.Equity.Adjustment.Factors.Basic.pdf).

<details>
<summary>**Advanced Filtering**</summary>

You can provide one or multiple filter expressions based on the dataset's columns to narrow down the results. For example, `StartDate.gt=2023-01-01&StartDate.lt=2023-12-31`, `Ticker=AAPL`. 

Please refer to the <a href="https://algoseek.com/docs/rest-api/tutorial/advanced-filtering">Advanced Filtering Guide</a> for the extensive reference.
</details>

## Query parameters

- `sort` string, nullable — Sorting criteria for the results. Provide a column name with optional prefix '+' for ascending order, or prefix with '-' for descending order. Multiple sorting fields may be supported depending on the dataset. If sort prefix is not provided, the ascending order is applied.
- `columns` string, nullable — A comma-separated list of columns to include in the response. Use this parameter to select only specific fields from the dataset. If not provided, all available columns will be returned.
- `offset` integer — Number of records to skip before returning results. To be used with the `limit` parameter for pagination. If not provided, defaults to 0.
- `limit` integer — Maximum number of records to return. Default and maximum values depend on the response format; see `format_limits` in the schema for details.
- `response_format` 'json' | 'csv' | 'csv_gzip' — Note the lowercase which is used for the consistency with other projects and tools

## Response `200`

JSON, CSV file, or gzip-compressed CSV file, depending on the value of `response_format` query parameter

- USEquitiesBasicAdjustmentFactorsDataOut
  - `data` USEquitiesBasicAdjustmentFactorsDataDetailsOut[], required
    - `ASID` integer, nullable — A unique identifier for a security
    - `Ticker` string, nullable — Symbol name
    - `EffectiveDate` string, date, nullable — The date on which the event becomes effective
    - `AdjustmentFactor` number, nullable — The value of the Adjustment factor for the event
    - `AdjustmentReason` string, nullable — The reason for the Corporate Event
    - `EventId` string, nullable — Unique Event ID under the AdjustmentReason
  - `pagination` PaginationDetailsOut, required
    - `offset` integer — The number of records skipped to fetch the current page
    - `limit` integer, required — The maximum number of records in the current page
    - `next_offset` integer, nullable — The number of records to skip to fetch the next page

## Other responses

- `403` — Forbidden
- `422` — Validation Error
- `429` — Request rejected because the identity or team exceeded a configured monthly or per-minute usage quota. When available, the response includes rate-limit headers describing the current quota.

---

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