What Do the Extensions Mean on Ticker Symbols?

Ticker symbol extensions are additional letters added to a security identifying it as something other than a single issue of capital stock or common stock. These extensions are known as "fifth-letter identifiers" or "fifth letter codes" for NASDAQ and Over the Counter (OTC) Bulletin Board stocks. On the other hand, the symbols are "behind the dot" codes for shares traded on the NYSE exchanges (New York Stock Exchange) because extension symbols are added after a period after a NYSE ticker name.

Read More​: What Does NASDAQ Consist Of?

The History of Ticker Symbols

Ticker symbols are abbreviations of a company's name, originally developed to transmit stock trade information by telegraph with fewer letters than a full name. The Standard & Poor's Co. brought uniformity to trading symbols by assigning a single letter combination to each company traded on a U.S. exchange.

Ticker symbol extensions serve the same function as company name abbreviations, with the Securities and Exchange Commission providing uniform letter extension symbols and definitions for companies, subject to the agency's regulation.

Read More​: NASDAQ Stock Market History

Neutral Symbol Extensions

Ticker symbol extensions have been assigned to every letter from A to Z in the NASDAQ and NYSE exchanges. One common two-letter extension is .PK, denoting a stock traded on the Pink Sheets, an over-the-counter stock quotation system.

While all symbols provide more information about a particular share, some are more benign than others. "A" is a class A share, while "B" is a class B share. An example of a behind-the-dot listing for these extensions is Berkshire Hathaway, which trades class A (BRK.A) and class B (BRK.B) on the NYSE.

A company can have voting (J) and nonvoting (K) shares or sell securities with a first (G), second (H) or third (I) convertible bond. Preferred stock can enjoy fourth (M), third (N), second (O) or first (P) preferred status. Shares can also be new (D) or foreign (F).

Added Rights Symbols

Certain symbols grant security holders additional rights in addition to a common share. Not surprisingly, the extension symbol for "rights" is R.

Since all symbols are abbreviations, to find what rights are given with a particular security, potential purchasers need to read company SEC filings and press releases for more details.

Investors can purchase shares the following symbols: of beneficial interest (S), with warrants or with rights (T), units (U), and when issued and when distributed (V). Also, the W at end of stock symbol (W) means with warrants. Seeing an "X" as the last identifier letter denotes a mutual fund.

Stock Warning Extensions

The two biggest potential warning symbols are E (delinquent in SEC required filings) and Q (bankruptcy).

It is worth noting though, that NASDAQ now uses the Financial Status Indicator instead of E or Q symbols. It does that to indicate the company has been delinquent in making the SEC regulatory filings, filed for bankruptcy, or failed to meet the exchange’s continuing listing standards. However, other markets may continue to use the E and Q symbols.

Remaining Single Extensions

Rounding out the alphabet of one letter extensions is "C," given when the issuer has been granted an extension of qualification standards by NASDAQ for a limited time. Miscellaneous situations get an L or a Z, and Y denotes an American Depositary Receipt.

Potential Confusion With Extensions

To provide global market information coverage, Reuters news service pairs up thousands of stock symbols and more than 100 different stock exchange designations with its Reuters Instrument Codes (RICs). RICs can appear in headlines, captions, titles, stories and metadata, according to the company. Confusion can occur when RICs are not removed before general publication.

For example, Microsoft's NASDAQ symbol becomes MSFT.O, with O being the RIC symbol for NASDAQ. The symbol does not mean Microsoft is offering second preferred stock, the SEC fifth-letter identifier for O.

Thankfully, RIC does not designate any exchange with an E, and the Q code identifies the Japan OTC market. While Bloomberg uses a set of proprietary exchange and country codes, none of them is a single letter.