technical analysis 6 - trend lines and trading

Technical Analysis VI: Trend Lines

What are Trend lines?
Trend lines are lines drawn on the historical price levels that depict general direction of where the marking is heading, and provide indications of support or resistance.
Drawing trend lines is a highly subjective matter. The best test of whether a trend line is a valid one is usually whether it looks like a good line. In an up trend, a trend line should connect the relative low points on the chart. A line connecting the lows in a longer-term rally will be a support line that can provide a floor for partial retracements. The down trend line that connects the relative highs on the chart will similarly act as resistance to shorter moves back higher.

Any two relative highs or lows will be on the same line, so it is possible to draw a tentative trend line between any two points. Traders can use tentative trend lines as an indication of where support or resistance might be, but until a tentative line holds as support or resistance, it is not yet confirmed as valid.
Of course, the more times a trend line holds, the stronger it will be in the future. If a single line can connect 4 or 5 relative lows, then the chances of the next pullback bouncing off the line are high.
The best trend line?
It is an unusual situation where three points on a chart will exactly coincide with a straight line connecting them. More often, prices will be close to a line, and a best-fit line will have to suffice. This is where trend lines become more art than science. Different traders may draw different trend lines given the same chart or even connecting the same series of relative low points.
Sometimes a trend line will have to be revised as new relative highs or lows appear. Even if the trend line is a very close fit between three or more points, it is important to be flexible and redraw trend lines when necessary.

Using High/Low or Close/Open
Often the differences in drawing trend lines depend on whether the high and low prices are used or whether the closing and opening prices are used to determine the line. On a candlestick chart, the question becomes using the wicks of the candlesticks instead of the solid bodies of the candles only.

Generally closing prices are more significant points than the intra-day prices on a chart, and if a trend line can be drawn using the body rather than the wick of a candle, the body should be used. Similarly, when drawing a trend line, an intra-day spike through a line should not automatically invalidate it. If there is a candle that closed below the trend line, though, it would be a much more serious breach of the line.

Only one of two things can happen when a price approaches support or resistance: the price can break through it, or it can bounce off and reverse direction. The same is of course true for trend lines.
1. Trading on a Pullback
If a chart is trending in a clear direction, and a trend line can be drawn connecting a series of relative highs or relative lows, trading opportunities exist when the price approaches the trend line. If the price bounces off the trend line and resumes the trend in the original direction, this can be an excellent opportunity to enter the market in the direction of the dominant trend. This is often referred to as buying on a pullback in an up trend or selling into strength in a downtrend.

Buying on a bounce off such a support line can be done through a limit order just above the support.
2. Trading a Break of the Trend
The second possible trade is the break of the trend line, which can be traded just as any other broken support or resistance line. If a candle closes through a trend line to the downside, as in the example below, the proper entry point would be to sell once the price moves below the low of the breakthrough candle.

This ensures that the short term force is in the direction of the break lower. The opposite would be true for a break above a resistance line.