Moving averages are one of the oldest trading tools. Futures traders use moving averages to reveal the underlying trend behind short-term price variations. Moving averages are a valuable indicator that can be used with other indicators to trigger buy signals.
A simple moving average is the average of a series of closing prices over a set period of time. For example, to determine a 3-day moving average of a commodity, the closing prices for three consecutive days are added together and divided by 3. A 20-day moving average would add the closing prices for 20 days and divide by 20. The “moving” is created by re-adding and re-dividing each day. In recalculating, the earliest closing price is dropped and the newest closing price is added before the figures are averaged. In our example, you are always averaging 3 prices for the three most recent consecutive days; however, those days are progressing in time through the month; therefore, the average is “moving.”
Because they use information that has already taken place, moving averages are “lagging” indicators. They are also “trend following” indicators that are most useful in trending price patterns in which an uptrend or downtrend is firmly entrenched. Moving averages often serve as both support and resistance points.When graphed, horizontal, or “flatline” moving averages have no predictive value.
The most common moving averages, those touted on the financial networks are 20-, 40-, 50-, and 200-day averages. Also effective are 10-, 30- and 100-day averages. Some traders create their own moving averages at intervals that appeal to them: 12, 18, 21, etc. days. Determine the time periods you believe will be most effective and stick with them. As a rule of thumb, limit your charts to no more than 4 or 5 moving averages per chart to avoid confusion.
For more information about Bill McCready’s trading system, visit Futures Trading Secrets.