Moving average crossovers are another way to apply the indicator. When an MA with a shorter period crosses an MA with a longer period, a directional change could be underway. One of the most useful crossovers is the 50/200. These two key moving averages, with their longer-term timeframes, tend to be reliable. If the 50 DMA rises through the 200 DMA, more upside could be in store. The inverse in true when the 50 DMA descends through the 200 DMA.