Moving average crossover strategies have been found to be quite useful, but traders need to choose the proper moving averages for their trading strategy. A simple moving average typically lags price by too much to be useful in trading. Instead an exponential moving average should be used. Even better for moving average trading strategies is the use of the double exponential moving average (DEMA). Because the DEMA puts a far greater emphasis on the most recent prices its changes reflect price movements more rapidly. Many traders like to use a crossover strategy with DEMA tools, where a fast moving average such as the 10 period, crosses a slower moving average such as the 50 period.