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Beginner guide
What is a moving average?
A moving average is one of the simplest tools in investing: the average closing price of a stock over a set number of recent trading days. It smooths out day-to-day noise so the underlying direction is easier to see.
How a simple moving average is calculated
A simple moving average (SMA) adds up the closing prices for the last N trading days and divides by N. Each new trading day, the oldest price drops off and the newest is added, so the average "moves" along with the chart.
Say a stock closed at $10, $11, $12, $11 and $13 over five days. The 5-day moving average is:
($10 + $11 + $12 + $11 + $13) ÷ 5 = $11.40
If the next close is $14, the $10 drops out and the new 5-day average becomes ($11 + $12 + $11 + $13 + $14) ÷ 5 = $12.20.
Other versions exist. An exponential moving average (EMA) gives more weight to recent days so it reacts faster. The idea is the same: a smoothed line that summarizes recent prices.
What short and long averages show
- Short averages (5 or 10 days) follow the price closely and react quickly. They describe the last week or two.
- Medium averages (20 to 50 days) describe the past one to two months.
- Long averages (100 to 200 days) describe the bigger trend over many months. The 200-day average is one of the most widely watched lines in the market.
How to read price versus a moving average
The most common reading is simply whether the current price is above or below the average:
- Price above its average means the stock is trading higher than it has on average over that window, which is a sign of recent strength.
- Price below its average means it's trading lower than its recent norm, which is a sign of recent weakness.
Traders also watch when a short average crosses a long one. When a short average rises above a long average, the recent trend is stronger than the longer one. The opposite suggests recent momentum is fading. A 50-day average crossing above a 200-day average is nicknamed a "golden cross", and the reverse a "death cross". The names are dramatic, but these crossovers are descriptions of what already happened, not reliable predictions.
How StockSignalCheck uses moving averages
The short-term score on every stock page uses two simple moving averages: a 5-day and a 20-day. The score starts at a neutral 50 and moves up or down depending on whether:
- the price is above or below its 5-day average,
- the price is above or below its 20-day average,
- the 5-day average is above or below the 20-day average, and
- the price has risen or fallen over roughly the last 20 trading days.
Each stock page lists the exact reasons behind its score, so you can see which of these conditions are true right now.
The limits of moving averages
- They lag. An average is built from past prices, so it always confirms a move after it has started. By the time a long average turns, much of the move may be over.
- Sideways markets cause false signals. When a stock drifts in a range, price can cross its average back and forth many times, producing "whipsaws" that look meaningful but aren't.
- They say nothing about the business. A moving average doesn't know whether a company is profitable, indebted, cheap or expensive. A stock can be above every average and still be overvalued, or below them and financially strong.
- Window choice matters. A 5-day and a 200-day average can point in opposite directions at the same time. Neither is "right"; they answer different questions.
A quick checklist
- Check which time window you're looking at before drawing conclusions.
- Compare short and long averages to see whether recent action matches the bigger trend.
- Treat crossovers as context, not as buy or sell signals.
- Pair trend signals with research into the company itself.
Keep learning
This guide is for education only. It isn't personalized financial, investment or tax advice, and nothing here is a recommendation to buy or sell any security. Investing involves risk, including the possible loss of your money.