It's true that all mutual funds' tickers have an "X" at the end of their symbol. The reason for this is to distinguish between mutual fund tickers and other securities that also have ticker symbols (such as stocks and bonds). This way you will automatically recognize a mutual fund by the X at the end of its ticker. Another example of this is a money market fund, which will be followed by two Xs. (See also: Understanding the Ticker Tape.)
Another reason behind the extra letter is that it allows for more ticker possibilities. If all securities in the market were restricted to a four-symbol ticker, it would limit the overall number of possible combinations of tickers. By adding a classifying letter to a ticker symbol, such as an X, you greatly increase the number of possible tickers and available choices of tickers. (See also: What Do All of the Letters in a Stock Option Ticker Symbol Mean?)
Identifying Investment Types
There are other characteristics among tickers that may be of interest. Stocks that trade on the NYSE will have three or fewer symbols and never more than that. However, tickers on the Nasdaq have four letters. This lets the investor know immediately which exchange a stock is traded on.
If a Nasdaq stock has an "E" behind it, that means the company that issues the stock is behind in its reports to the Securities and Exchange Commission (SEC). The same goes for an NYSE stock that as an "LF" behind it.
Stocks in Asia use numbers instead of ticker symbols, while stocks on the London exchange are followed by ".L". Singapore stocks end in ".SI". In the United States, the symbol ".A" indicates class A shares.
Why Stock Tickers Are Important
In addition to identifying your mutual fund's symbol, you need to know how tickers work so you can understand a mutual fund's holdings. Often, fund reports list the holdings in the portfolio using ticker symbols, sometimes along with the stock's name and sometimes by themselves. Understanding the symbols lets you know what types of securities the fund holds. For example, if you are interested in a domestic stock mutual fund, but you see that it holds securities in other countries, you may want to steer clear of that one and choose a fund that is more purely domestic.
The Bottom Line
It is always a mistake to simply trust that a fund manager knows better than you do. You owe it to yourself to understand ticker symbols so you can follow what your fund is invested in. In addition, when you want to know the value of your mutual fund, you will need its ticker to look it up. (See also: My Stock's Ticker Symbol Recently Changed, Why Is This?)