Internal Trend Lines

Internal Trend Lines

Sometimes there appears to be the possibility for drawing a trend line, but the exact points do not match up cleanly. The highs or lows might be out of whack, the angle might be too steep or the points might be too close together.

If one or two points could be ignored, then a fitted trend line could be formed. With the volatility present in the market, prices can over-react, and produce spikes that distort the highs and lows. One method for dealing with over-reactions is to draw internal trend lines. Even though an internal trend line ignores price spikes, the ignoring should be within reason.


The long-term trend line for the S&P 500 ($SPX) extends up from the end of 1994, and passes through low points in Jul-96, Sept-98 and Oct-98. These lows were formed with selling climaxes, and represented extreme price movements that protrude beneath the trend line. By drawing the trend line through the lows, the line appears to be at a reasonable angle, and the other lows match up extremely well.


Sometimes, there is a price cluster with a high or low spike sticking out. A price cluster is an area where prices are grouped within a tight range over a period of time. The price cluster can be used to draw the trend line, and the spike can be ignored. The Coca Cola (KO) chart shows an internal trend line that is formed by ignoring price spikes and using the price clusters, instead. In October and November 1998, Coke formed a peak, with the November peak just higher than the October peak (1). If the November peak had been used to draw a trend line, then the slope would have been more negative, and there would have appeared to be a breakout in Dec-98 (gray line). However, this would have only been a two-point trend line, because the May-June highs are too close together (black arrows). Once the Dec-99 peak formed (green arrow), it would have been possible to draw an internal trend line based on the price clusters around the Oct/Nov-98 and the Dec-99 peaks (blue line). This trend line is based on three solid touches, and it accurately forecasts resistance in Jan-00 (blue arrow).