By TheStreet.com Staff What Is the Nasdaq Composite?When investors want to know how tech stocks, in general, are doing, they turn to the Nasdaq Composite Index. This index tracks the stocks listed on the Nasdaq Stock Exchange and is denoted with the symbol IXIC. Along with otherstock indexes like the S&P 500 and the Dow Jones Industrial Average (aka the Dow), the Nasdaq Composite Index is known as a bellwether index because it represents an entire category of investment, and its performance reflects big-picture economic trends. While the S&P 500 is known for large-cap stocks, and the Dow has s…