Trading Divergence and Understanding Momentum

Because trends are composed of a series of price swings, momentum plays a key role in assessing trend strength. As such, it is important to know when a trend is slowing down. Less momentum does not always lead to a reversal, but it does signal something is changing, and the trend may consolidate or reverse.

Price momentum refers to the direction and magnitude of price. Comparing price swings helps traders gain insight into price momentum. Here, we'll take a look at how to evaluate price momentum and show you what divergence in momentum can tell you about the direction of a trend.

Key Takeaways

  • Price momentum is measured by the length of short-term price swings—steep slopes and a long price swing represent strong momentum, while weak momentum is represented by a shallow slope and short price swing.
  • Momentum indicators include the relative strength index, stochastics, and the rate of change. 
  • Divergence—the disagreement between indicators—can have major implications for trade management.

Defining Price Momentum

The magnitude of price momentum is measured by the length of short-term price swings. The beginning and end of each swing are established by structural price pivots, which form swing highs and lows. Strong momentum is exhibited by a steep slope and a long price swing. Weak momentum is seen with a shallow slope and short price swing.

Image by Julie Bang © Investopedia 2019

For example, the length of the upswings in an uptrend can be measured. Longer upswings suggest the uptrend is showing increased momentum, or getting stronger. Shorter upswings signify weakening momentum and trend strength. Equal-length upswings mean the momentum remains the same.

Price swings are not always easy to evaluate with the naked eye because the price can be choppy. Momentum indicators are commonly used to smooth out the price action and give a clearer picture. They allow the trader to compare the indicator swings to price swings, rather than having to compare price to price.

Momentum Indicators

Common momentum indicators for measuring price movements include the relative strength index (RSI), stochastics, and rate of change (ROC). Figure 2 is an example of how RSI is used to measure momentum. The default setting for RSI is 14. RSI has fixed boundaries with values ranging from 0 to 100.

Momentum can be calculated by using the formula:

M = CP - CPx

Where CP is the closing price and CPx is the closing price "x" number of periods ago.

For each upswing in price, there is a similar upswing in RSI. When price swings down, RSI also swings down.

Figure 2: Indicator swings generally follow the direction of price swings (A). Trendlines can be drawn on swing highs (B) and lows (C) to compare the momentum between price and the indicator.

Source: TDAmeritrade Strategy Desk

The study of momentum simply checks whether price and the indicator agree or disagree.

Figure 3: Compare price and indicator to make better trading decisions.

Source: TDAmeritrade Strategy Desk

Momentum Divergence

Disagreement between the indicator and price is called divergence, and it can have significant implications for trade management. The amount of agreement/disagreement is relative, so there can be several different patterns that develop in the relationship between price and the indicator. For this article, the discussion is limited to the basic forms of divergence.

It is important to note there must be price swings of sufficient strength to make momentum analysis valid. Therefore, momentum is useful in active trends, but it is not useful in range conditions in which price swings are limited and variable, as shown in Figure 4.

Figure 4: In range conditions, the indicator does not add to what we see from price alone. Variable pivot highs and lows show range.

Source: TDAmeritrade Strategy Desk

Divergence in an uptrend occurs when price makes a higher high but the indicator does not. In a downtrend, divergence occurs when price makes a lower low, but the indicator does not. When divergence is spotted, there is a higher probability of a price retracement. Figure 5 is an example of divergence and not a reversal, but a change of trend direction to sideways.

Figure 5: Momentum divergence and a pullback. Higher pivot highs (small orange arrows) signal price support.

Source: TDAmeritrade Strategy Desk

Divergence helps the trader recognize and react appropriately to a change in price action. It tells us something is changing and the trader must make a decision, such as tighten the stop-loss or take profit. Seeing divergence increases profitability by alerting the trader to protect profits.

Technical traders generally use divergence when the price moves in the opposite direction of a technical indicator.

Take note of the stock from Figure 5, Chesapeake Energy (CHK), in which shares pulled back to the support. The chart in Figure 6 (below) shows trends do not reverse quickly, or even often. Therefore, we make the best profits when we understand trend momentum and use it for the right strategy at the right time.

Figure 6: Trend continuation. Agreement between price and the indicator give an entry (small green arrows).

Source: TDAmeritrade Strategy Desk


Four Commonly Used Indicators In Trend Trading

Managing Divergence

Divergence is important for trade management. In Figure 5, taking profit or selling a call option were fine strategies. The divergence between the price and the indicator lead to a pullback, then the trend continued. If you look at the pivot the price makes below the lower trendline, this is often referred to as a bear trap, where the false signal draws in shorts and price quickly reverses. The signal to enter appeared when the higher low in price agreed with the higher low of the indicator in Figure 6 (small green arrows).

Divergence indicates something is changing, but it does not mean the trend will reverse. It signals the trader must consider strategy options—holding, selling a covered call, tightening the stop, or taking partial profits. The glamour of wanting to pick the top or bottom is more about ego than profits. To be consistently profitable is to pick the right strategy for what price is doing, not what we think price will do.

Figure 7: Divergence results in range.

Source: TDAmeritrade Strategy Desk

Figure 7 shows a divergence that leads to sideways price action. Notice the weakening momentum in moving average convergence divergence (MACD) as price enters a range. This signals the trader should consider strategy options. When price and the indicator are inconsistent relative to each other, we have a disagreement, or divergence. We are not in control of what price will do. Instead, we control only our own actions.

Figure 8: Divergence and then reversal of trend.

Source: TDAmeritrade Strategy Desk

Sometimes divergence will lead to a trend reversal, as shown in Figure 8. The Utilities Select Sector SPDR (XLU) shown in Figure 9 pays a dividend and has options. Understanding trend momentum gives investors a profit edge, as there are three ways to profit here: capital gains, dividends, and call premium. This example shows trend continuation after a sideways move, which translates into profit continuation.

Figure 9: Go with the trend when the price and the indicator agree.

Source: TDAmeritrade Strategy Desk

The Bottom Line

The most useful way to use a momentum indicator is to know what strategy to use. Price will lead the way, but momentum can indicate a time to preserve profits. The skill of a professional trader lies in their ability to implement the correct strategy for price action.