What are Moving Averages?
A moving average takes the closing prices of a share or index over a specified number of periods and calculates their average. That average then “moves” forward as new price data arrives and old data drops off. The result is a smoothed line that sits on your chart, showing you the general direction price has been travelling without all the daily ups and downs. There are three common types: Simple moving average (SMA) adds up the closing prices over your chosen period and divides by the number of periods. Every price in the lookback window gets equal weight. A 20-period SMA on a daily chart averages the last 20 days of closing prices. Traders will often use the 8SMA for day trading, the 50SMA for medium term trend, and the 200SMA for longer term trend identification. Exponential moving average (EMA) gives more weight to recent prices, making it more responsive to new information. It reacts faster to price changes than an SMA but still lags behind the current price. Many traders prefer EMAs for shorter-term strategies because they hug price more closely. Weighted moving average (WMA) assigns a linear weight to each price in the period, with the most recent price receiving the highest weight. It sits somewhere between the SMA and EMA in responsiveness. All three types smooth price, all three lag, and none of them predict where price will go next.How They Work
Let’s walk through a simple example using a 10-period SMA on a daily chart. You take the closing prices for the last 10 days, add them up, and divide by 10. Tomorrow, you drop the oldest day, add the newest closing price, and recalculate. The line shifts forward one day at a time. The longer your period, the smoother the line and the greater the lag. A 200-day SMA smooths out months of price action but reacts very slowly to sudden moves. A 10-day SMA responds faster but gets whipsawed more easily in choppy conditions. Lag is not a flaw to be fixed. It’s the trade-off you accept when you choose to smooth data. If you want less lag, you’ll get more noise and more false signals. If you want more smoothing, you’ll react slower to genuine trend changes. Neither choice is inherently better. The right one depends on your strategy, timeframe, and risk tolerance. Most charting platforms and stock brokers in Australia include moving averages as a standard indicator, so you won’t need to calculate them manually. You’ll just select the type, choose your period, and the software does the rest.How To Use Moving Averages
Traders use moving averages in a few main ways, though none of them work reliably in isolation.Trend confirmation
When price is above a rising moving average, traders interpret that as a sign the trend is up. When price is below a falling moving average, the trend is considered down. This doesn’t mean price will keep moving in that direction, but it gives you a reference point for bias. You can then watch how the price reacts to a moving average within a trend, either for confirmation, or breakdown.Slope as a direction signal
The slope of the moving average itself can tell you something about trend strength. A steep upward slope suggests strong momentum. A flat or choppy moving average often coincides with sideways price action. Some traders won’t take trades unless their chosen moving average is sloping in the direction they want to trade.Dynamic support and resistance
Many traders talk about moving averages acting as support in uptrends or resistance in downtrends. In reality, moving averages don’t “act” as anything. They’re just lines on a chart. What actually happens is that when enough traders watch the same moving average, price sometimes bounces near it because those traders are placing orders there. It’s a self-fulfilling setup, not a law of physics. Sometimes it works. Sometimes price slices straight through. You need confirmation from actual price behaviour before assuming a moving average will hold.Crossover strategies
When a shorter-period moving average crosses above a longer-period moving average, it’s considered a bullish signal. When it crosses below, it’s bearish. These signals can work in trending markets but generate expensive whipsaws in choppy conditions. Crossovers are lagging by design, so you’ll often enter well after the move has started. A couple of the major crosses include the golden cross (50SMA crossing above the 200SMA), and the death cross (50SMA crossing below the 200SMA).What the evidence says
What the setup is trying to capture: Moving averages attempt to identify and ride trends by filtering out short-term noise. The assumption is that trends persist long enough for a lagging indicator to still capture a meaningful portion of the move. Best use case: Strong, sustained trends in liquid markets. When a share or index is trending clearly for weeks or months, moving average strategies can capture a decent chunk of the move. They work better on longer timeframes (daily, weekly) than on intraday charts. Weakest use case: Choppy, sideways, or low-volatility markets. Moving averages produce frequent whipsaws when price oscillates around the average without establishing a clear trend. Available win-rate and return data: Studies of simple moving average crossover systems on major indices show win rates typically between 35% and 50%, depending on the periods used and the market studied. Profitability depends entirely on whether winning trades are large enough to offset frequent small losses. Some trend-following funds have used moving average-based systems successfully over decades, but they accept long drawdown periods and rely on position sizing and diversification. Practical takeaway: A high win rate is not the same thing as a profitable strategy. Moving average systems often have win rates below 50% but can still be profitable if winners are significantly larger than losers. If you’re going to use moving averages, you need to accept frequent small losses and have the discipline to let winners run when trends develop.Common mistakes
Treating moving averages as standalone signals: A crossover or a price touch on a moving average isn’t enough information to take a trade. You need context from price structure, volume, support and resistance levels, and broader market conditions. Over-relying on crossovers: Crossover signals lag significantly. By the time a golden cross forms, the trend may already be mature. Some traders use crossovers to confirm what they already see in price structure rather than as primary entry triggers. Ignoring price structure: If you’re watching a moving average but ignoring key support and resistance levels, breakout zones, and candlestick patterns, you’re missing the most important part of the chart. Price structure tells you where supply and demand actually showed up. Moving averages tell you what the average was. Using the same periods in all markets: A 50-day moving average might work well on a large-cap ASX stock with steady trends, but it could be useless on a volatile small-cap that swings wildly every few days. Adjust your periods to match the market’s behaviour. Expecting dynamic support to work every time: Just because price bounced off a moving average last week doesn’t mean it will this week. Moving averages don’t exert any force on price. If buyers don’t show up, price will cut through your moving average like it’s not there.When it works best
Moving averages shine in specific conditions, in particular strong trending markets. When a share or commodity is in a clear uptrend or downtrend, moving averages help you stay on the right side of the move. They filter out counter-trend noise and keep you focused on the dominant direction. Daily and weekly charts tend to produce more reliable moving average signals than intraday charts. The longer the timeframe, the less noise and the more meaningful the smoothing. If you’re building a mechanical trading system, moving averages are useful because they’re objective and easy to code. They remove discretion and force you to follow your rules. Some traders will also use moving averages as trailing stops. For example, they might exit a long position if price closes below the 20-day EMA. This approach locks in profits during trends and gets you out when momentum fades.The bottom line
Moving averages are simple, widely available, and useful for adding context to your trading decisions. They smooth out noise, help you identify trend direction, and can form the backbone of rule-based strategies. But they lag, they don’t predict, and they’ll churn out losing trades in choppy markets. If you’re going to use moving averages, use them as part of a complete strategy that includes price structure, risk management, and realistic expectations about win rates. Don’t treat them as magic lines that will tell you when to buy and sell. They’re tools for context and confirmation, not crystal balls. Ask yourself whether the market you’re trading is actually trending. Ask whether your timeframe is suitable. Ask whether you’re prepared for the lag and the whipsaws. And most importantly, ask whether you’ve defined your risk before you enter the trade. Moving averages can help you stay on the right side of a trend, but they won’t do the hard work of trade management for you. You will see traders watching an index for a broad trend, looking for tests of the 50day and 200day SMAs, and broadly they are looking for either confirmation of a trend, or a potential level of friction and reversal. For more, check out our guide on how to use simple moving averages in your trading.TL;DR
- Moving averages smooth price data but always lag behind current price action
- Common types include simple moving average (SMA), exponential moving average (EMA), and weighted moving average (WMA)
- They’re most useful in trending markets and weakest in choppy, sideways conditions
- Slope and position relative to price can signal trend strength, but not predictively
- High win rates don’t guarantee profitability if risk/reward is poor
- Moving averages work best as context tools within a complete trading strategy
