Using Indicators to Identify Trends
Of the many market sayings thrown around by traders, perhaps none is more overused and less understood than the old adage ‘the trend is your friend’. All too often, the phrase is used after a trader has taken a counter-trend position and subsequently been stopped out at a loss. Remorse sets in at this point and most traders kick themselves not only for having lost on a counter-trend trade, but also for not having caught the latest move in the trend itself.
To avoid this all too common scenario, we will suggest using several technical tools to identify whether or not a trend is in place and then use additional indicators to help maximize trading profits. Having a strategy in place to identify trends is essential to successful trading in any market, but especially so in the case of the forex markets. Currencies have a greater tendency to move in trending fashion due to the longer-term macroeconomic elements that drive exchange rates, such as interest rate cycles or global trade imbalances. Currencies are also pre-disposed to short-term, intra-day trends due to international capital flows reacting in unison to day-to-day economic and political news.
Identifying the Trend
In its most basic sense, a trend is simply a prolonged market movement in one general direction, either up or down. From a traders’ perspective, though, that simple definition is so broad as to be relatively meaningless. A more relevant definition of a trend would be one where a trend is defined as a predictable price response at levels of support/resistance that change over time. For example, in an uptrend the defining feature is that prices rebound when they near support levels, ultimately establishing new highs. In a downtrend, the opposite is true-price increases will reverse as they near resistance levels, and new lows will be reached. This definition reveals the first of the tools used to identify whether a trend is in place or not-trendline analysis to establish support and resistance levels.
Trendline analysis is often underestimated because it is perceived as overly subjective and retrospective in nature. While both criticisms have some truth, they overlook the reality that trendlines help focus attention on the underlying price pattern, filtering out the noise of the market. For this reason, trendline analysis should be the first step in determining the existence of a trend. If trendline analysis does not reveal a discernible trend, it’s probably because there isn’t one.
Trendline analysis is best employed starting with longer timeframes (daily or weekly charts) first and then carrying them forward into shorter timeframes (hourly or 4-hourly) where shorter-term levels of support and resistance can then be identified. This approach has the advantage of highlighting the most significant levels of support/resistance first and less important levels next. This helps reduce the chances of following a short-term trendline break while a major long-term level is lurking nearby.
Another technical tool that can be deployed to verify the existence of a trend is the directional movement indicator system (DMI), developed by J. Welles Wilder (see Wilder, New Concepts in Technical Trading Systems, c. 1978). Using the DMI removes the guesswork involved with spotting trends and can also provide confirmation of trends identified by trendline analysis. The DMI system is comprised of the ADX (average directional movement index) and the DI+ and DI- lines. The ADX is used to determine whether or not a market is trending (regardless if it’s up or down), with a reading over 25 indicating a trending market and a reading below 20 indicating no trend. The ADX is also a measure of the strength of a trend–the higher the ADX, the stronger the trend. Using the ADX, traders can determine whether or not there is a trend and thus whether or not to use a trend following system.
As its name would suggest, the DMI system is best employed using both components. The DI+ and DI- lines are used as trade entry signals. A buy signal is generated when the DI+ line crosses up through the DI- line; a sell signal is generated when the DI- line crosses up through the DI+ line. (Wilder suggests using the “extreme point rule” to govern the DI+/DI- crossover signal. The rule states that when the DI+/- lines cross, traders should note the extreme point for that period in the direction of the crossover (the high if DI+ crosses up over DI-; the low if DI- crosses up over DI+). Only if that extreme point is breached in the subsequent period is a trade signal confirmed.
The ADX can then be used as an early indicator of the end/pause in a trend. When the ADX begins to move lower from its highest level, the trend is either pausing or ending, signaling it is time to exit the current position and wait for a fresh signal from the DI+/DI- crossover.