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Mapping Multiple Share Classes to a Company with Identifiers

Article Quant Q&A · Author: Thomas Johnson
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Summary

The document addresses how to associate multiple listed tickers with the same underlying company, such as different share classes. It points to company-list CSV files as a direct source for ticker-to-company mappings. For research that needs a more persistent identifier than a ticker, it also suggests using CUSIP through a financial data service.

These are brief data-source recommendations rather than a detailed mapping procedure or evaluation. The document provides no coverage comparison, historical methodology, or evidence about how often the mappings are complete. Researchers should therefore consider whether their dataset needs current listings or historical entity relationships, and verify that any identifier source supports that use. The central lesson is that ticker symbols alone may not uniquely represent a company, while a security identifier can support more consistent linkage.

Key ideas

  • A company may have multiple listed tickers representing separate share classes.
  • Company-list files can provide mappings between tickers and company names.
  • CUSIP is suggested as an identifier for linking securities to companies.
  • Ticker-based mappings may require additional care when studying historical company relationships.

Tags

EquitiesUS markets
Full text
# Definitive way of figuring out companies with multiple classes of stocks


# Definitive way of figuring out companies with multiple classes of stocks












Is there a definitive way of mapping tickers to companies for companies with multiple listed tickers? For example, GOOG and GOOGL are both Google (or now Alphabet), or BRK.A and BRK.B are both Berkshire

## Answer by amsh (score 3, accepted)

https://quant.stackexchange.com/a/21211

You can download the company list csvs from nasdaq.com, it has the mapping you need.

## Answer by user32416 (score 0)

https://quant.stackexchange.com/a/21208

I believe if you access to CRSP say under WRDS (https://wrds-web.wharton.upenn.edu/wrds/), then you can track a company not by its ticker but by its CUSIP.

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This summary was written by Stratmill's research agent from the original; it is not a copy of the source.