Tells Me: The price is generally in an established trend (bullish or bearish) for the time horizon represented by the moving average periods. Moving averages (MA) are used to smooth out the volatility or "noise" in the price series, to make it easier to discover the underlying trend. By plotting the average price over the last several bars, the line is less "jerky" than plotting the actual prices. In the double crossover method, a bullish event is generated when a faster moving average crosses above a slower moving average (21-bar MA crosses 50-bar, or 50-bar MA crosses 200-bar). In this state, the price is likely in an established uptrend. The opposite is true when the faster slips below the slower moving average, triggering a bearish event.