Financial Dictionary
Crossover
The point on a stock chart when a security and an indicator intersect. Crossovers are used by technical analysts to aid in forecasting the future movements in the price of a stock. In most technical analysis models, a crossover is a signal to either buy or sell.
Below we have a stock that falls below its 20-day moving average - a bearish sign.

Investopedia Commentary
An example of a crossover would be when the security line breaks through its 25-day moving average which may be a signal to buy the stock. Some of the indicators that use crossovers are "moving average" and "Bollinger bands".
Related Links
Introduction To Technical Analysis
The Basics of Bollinger Bands
Price Patterns - Part 1
Simple Moving Averages and Volume Rate-of-Change
See also: Bollinger Band, Chartist, Indicator, Moving Average, Moving Average Chart, Technical Analysis
Also spelled: Cross Over, Crossover