There are many tools and methods traders use to determine the trend on a particular stock or index. One objective method which was popularized by the founder of Stockcharts.com, John Murphy, is the crossover of two moving averages namely the 13-day exponential and the 34-day exponential. The chart below depicts the crossovers of these two moving averages during the past year on the SPDR S&P 500 (SPY) etf. When the faster 13-day exponential moving average crosses below the slower 34-day exponential moving average the conclusion is that the current trend is now down. The flip side works when the same, i.e. when the 13 ema crosses above the 34 ema one can consider the trend to be up. One warning though, is moving average crossover-type systems can offer up some whipsaw-type action. As you can observe on the chart once a signal is triggered a reversal is not uncommon. So, this morning the 13-day has crossed beneath the 34-day moving average for the first time since late June. But do not be surprised if we see a reflex rally.