Anyone who has worked with historical equity or options data understands the challenges that arise when companies change ticker symbols or other identifiers. This can occur when a company changes from one listing exchange to another, from an acquisition or spinoff, if a more desirable ticker symbol becomes available, etc. It happens more often than most people realize. TickWrite® uses this information to output time series data files mapped for these events.
As-Traded vs. Mapped Data
When analyzing historical data, it is important to distinguish between “as-traded” and “mapped” data. Any historical data vendor can provide raw, as-traded equity and option data files that are named by the symbols under which they traded on a given date. The challenge is knowing what companies these symbols represented at the time. Without this information, the as-traded files are not only useless, but can cause users to perform research on the wrong companies.
To eliminate this problem, Tick Data has researched the corporate actions of every company in every market for which we provide equity and option data and produced a complete “symbol map.” A symbol map is the set of instructions for how to assemble as‐traded symbols into a complete time series for a particular security.
For example, the company today named Citigroup, Inc. trades under the symbol C, and has had the following corporate actions since our data began in 1993:
C = C + CCI + TRV + PA, with three name changes and five CUSIP changes as well.
We embed this information in our TickWrite® data management software, which we include with all orders. When a client requests the current ticker C, TickWrite uses its symbol map to link together files named by all of the symbols it needs to generate the file. This allows clients to write out mapped time series files custom-formatted to their requirements without any need for additional information.
For clients who want access to this information outside of TickWrite®, for use in their own databases or internal processes, we make this information available in plain text for an additional fee. Click here to learn more about our Company Info/Ticker Mapping® product.