An indicator is a mathematical calculation that can be applied to a security's price and/or volume fields. The result is a value that is used to anticipate future changes in prices.
A moving average fits this definition of an indicator: it is a calculation that can be performed on a security's price to yield a value that can be used to anticipate future changes in prices.
The following chapters (see page ) contain numerous examples of indicators. I'll briefly review one simple indicator here, the Moving Average Convergence Divergence (MACD).
