What’s Inside a Moving Average? How These Simple Indicators Help Us Profit

It’s amazing how many things in our lives we use–and benefit from–and have no idea how they work.  For example, I know there are spark plugs under the hood of my Lexus SUV. Do I know how they work within the car’s engine to move me up the street?  No clue.  In the rare instance I feel a headache coming on, I pop a Tylenol and wait for the pain to subside. Do I have any idea how Tylenol or aspirin actually block the pain? Nope. When I turn on the kitchen lights, do I think about the path the electricity has taken from the Florida Power & Light grid into my home? No. I take it for granted.

Just so, many of us who use price charts plotted with moving averages to track our stocks may not think about the actual construction of the moving average indicator—nor do we want to. After all, few things on God’s green earth are as mind-tangling as chart indicator calculations.

That being said, I’m going to posit that as traders and investors, if we have a deeper understanding of moving average construction—and this calculation is easy peasy—that knowledge will lead us to higher profits.

I say “higher profits” because moving averages are terrific decision-support tools. Used appropriately, we can combine the perspective they offer with price, volume and additional indicators to indicate buying opportunities, plan risk management, and determine exit strategies.

A moving average is a single-line indicator we plot on our price charts to give us a running average of price over a pre-determined time period. If the price of our stock, exchange traded fund, or other asset is trading above the moving average line, then we know that price is currently stronger than the assigned average. Should price be trading beneath the moving average line, then it is currently weaker than the assigned average price.

Want to plot a 50-day moving average for Whizzy Widgets? Write down Whizzy’s closing prices for the last 50 trading days. Add them together. Divide the sum by 50. Get out your pencil and put a dot on Whizzy’s price chart on today’s date.

Tomorrow, when Whizzy closes for the day, add that price to your list of closing prices. Then remove the earliest price from the list. Once again, total your updated list of (50) prices. Divide the sum by 50. Mark another dot on Whizzy’s price chart at tomorrow’s date. Now, draw a line connecting the two dots. Voila!  You’ve constructed a moving average.

On a daily chart, we many times plot 20-day moving averages, because there are 20-21 trading days in a month. If our stock’s price trades above the 20-day line, we know it is stronger than the most recent 20 days of closing prices.

We may also plot a 50-day moving average, because that is an average tracked by many institutions. Institutional traders and investors are the big money folks who move markets. So, if they watch the 50-day moving average, then we are wise to watch the 50-day moving average. (The institutions generally prefer stocks trading above the 50-day line.)

The slow and lumbering 200-day moving average is another well-watched guideline. Since there are 240-250 trading days in the year, if our stock is trading above the 200-day line, and the 200-day line is rising, then our stock is relatively “healthy.” Should the stock fall below that line, especially for more than a week, it may be feeling feeble.

On this daily chart of the Walt Disney Co. (DIS), we can see that for much of the year, Disney has trended higher above its rising 20-day (red), 50-day (green), and 200-day moving averages (black)—an ideal scenario for investors.

Walt Disney Co. (DIS) Daily Chart

DIS_Daily_Chart_Nov23

Chart courtesy RealTick

When I captured this chart, Disney stood just atop its 50-day moving average. If Disney can use this line for support–and traction–then it should be able to continue its uptrend. If the media giant slips below the 50-day MA (moving average), however, then short-term investors may take profits. Others may keep an eye on the 200-day MA for longer-term support, and take gains if Disney falls below that line.

We may not know how the “thingamagibbits” under the hoods of our car propel us down the highway, or how aspirin cures our headaches.  But knowing how moving averages are constructed and how they work on our price charts can help us become more successful traders and investors.

Until next time, keep green on your screen!

Toni Turner