Moving Average Crossovers May Not Be The Best Entry Signals
There are many ways of using moving averages to trade but by far the most
common method is to trade when a short-term moving average crosses over a longer
term moving average. For example, if the 10-day MA crosses above the 30-day MA
we typically assume that we have a new buy signal.
Let's stop for a minute and think about what exactly is occurring at the point
of a crossover. When the 10-day MA and the 30-day MA are at the same price, the
trend is not nearly as clear as it should be. What we are really observing at
the crossover point is that the average of the last 30 prices is exactly the
same as the average of the last 10 prices. If we are looking for trends to
trade, this equal relationship of the two moving averages is not a reliable or
logical indication of a trend. In an upward trending market the average prices
over the last 10 days should be much higher than the average of the last 30
days. By implementing new trades at crossover points we are limiting our trading
to points that may not clearly reflect what we should be doing. For best results
in a trend-following system we want to be trading when the trend is clear and
reliable; not when the trend is confused and questionable.
Instead of trading at crossovers we should be implementing our trades when the
moving averages are parallel or when the short-term moving average is moving
farther away from the longer-term moving average. Perhaps the short term MA
should remain a minimum of some units of Average True Range above the longer
term MA for several days. I believe that this procedure would give us more
reliable and more frequent entry signals in the direction of the prevailing
trend, which is exactly what we want. To identify the most reliable trends we
want to see the slopes of various moving averages all moving steadily in the
same direction and not crossing back and forth.
Take a look at a chart of any market with a strong trend. You will see that the
moving averages are not crossing back and forth repeatedly. They will be moving
in the same general direction in a more or less parallel fashion. Now look at a
chart of a non-trending market. As this market moves sideways the moving
averages will be crossing back and forth very frequently. Look at the
implications of this simple examination of the charts. If we are trading the
crossovers we will be trading most frequently in non-trending markets and
trading most infrequently in strongly trending markets. Is that what we want?
No, it's obviously not what we want. We want just the opposite. We want frequent
entry opportunities in trending markets and we want to avoid as many trades as
possible in non-trending markets.
The error in the logic of trading moving average crossovers also extends to some
interpretations of MACD (Moving Average Convergence and Divergence) and DMI
(Directional Movement Indicator). If we are looking at MACD we want to see both
lines (each line reflects a moving average relationship) moving in the same
direction. We don't want to see them crossing. When looking at DMI we want to
see the Plus DI lines and the Minus DI lines moving in opposite directions and
definitely not crossing. Remember, when the Plus DI and the Minus DI lines
intersect it is telling us that the market is in balance and has no direction;
the amount of upward and downward directional movement are exactly equal. What
makes our favorite indicator, the ADX, so effective is that it rises only when
the Plus DI and the Minus DI are moving in opposite directions and the distance
between the two indicators is widening.
With a little thought and effort I'm sure we can design some reliable entry
signals that are based on moving averages but avoid the typical crossover
signals. For example we could measure the slope of several moving averages and
when all the averages slope upward we would have a buy signal.
We could also measure the distance between several moving averages and implement
our trades when the averages are all headed in the same direction but start
getting farther apart. This procedure would give us a series of entry signals
within the same original trend. This should provide an excellent entry and
re-entry strategy.