A ticker symbol or stock symbol is an abbreviation used to uniquely identify publicly traded of a particular on a particular . A stock symbol may consist of letters, numbers or a combination of both. "Ticker symbol" refers to the symbols that were printed on the ticker tape of a ticker tape machine.
Stock symbols are unique identifiers assigned to each security traded on a particular market. For example, AAPL is for Apple Inc.; OODH is for Orion DHC, Inc., and HD is for Home Depot, Inc. A stock symbol can consist of letters, numbers, or a combination of both, and is a way to uniquely identify that stock. The symbols were kept as short as possible to reduce the number of characters that had to be printed on the ticker tape, and to make it easy to recognize by traders and investors.
The allocation of symbols and formatting convention is specific to each stock exchange. In the US, for example, stock tickers are typically between 1 and 4 letters and represent the company name where possible. For example, US-based computer company stock Apple Inc. traded on the NASDAQ exchange has the symbol AAPL, while the motor company Ford's stock that is traded on the has the single-letter ticker F. In Europe, most exchanges use three-letter codes, for example Dutch consumer goods company Unilever traded on the Amsterdam Euronext exchange has the symbol UNA. While in Asia, numbers are often used as stock tickers to avoid issues for international investors when using non-Latin scripts. For example, the bank HSBC's stock traded on the has the ticker symbol 0005.
Symbols sometimes change to reflect mergers. Prior to the 1999 merger with Mobil Oil, Exxon used a phonetic spelling of the company "XON" as its ticker symbol. The symbol of the firm after the merger was "XOM". Symbols are sometimes reused, in the US the single-letter symbols are particularly sought after as vanity symbols. For example, since Mar 2008 Visa Inc. has used the symbol V that had previously been used by Vivendi which had delisted and given up the symbol.