A moving average smooths price into a single line by averaging the last N closes. A 50-period average plots the mean of the last 50 candles and re-plots every bar, filtering out the noise so the underlying trend is easier to see. The simulator offers simple, exponential, weighted and Hull versions.
What it measures
The two you will use most are the SMA (simple moving average), which weights every candle equally, and the EMA (exponential moving average), which weights recent candles more heavily so it reacts faster. A shorter period hugs price and turns quickly; a longer period is smoother and slower. There is no correct number - a 20 EMA and a 200 SMA answer different questions about different timeframes.
How to read it
Where traders get it wrong
The classic trap is trading crossovers mechanically. Because a moving average is built from past prices, a crossover confirms a move that has already happened - great in a strong trend, terrible in a range where it whipsaws you into loss after loss. Moving averages are a trend filter, not a signal generator. The full crossover approach, and its weaknesses, are covered in the moving average crossover strategy.
An indicator confirms, it does not command. The signal is a reason to look, not an order to trade. Combine it with levels and the trend, and size every trade with the position size calculator so a false signal costs a small, fixed amount.
What the measured data says
We ran every common moving-average signal against a matched-risk random entry across 28 instruments and 232,772 signals, with real measured spreads applied. The headline result is unkind to the most famous signal of the lot: the golden cross has a negative edge.
| Signal | Trades | Win rate | Matched random | Edge | Significance |
|---|---|---|---|---|---|
| Death cross (EMA 50/200) | 333 | 49.2% | 46.8% | +2.5 pts | not significant |
| EMA 9/21 bear cross | 2,438 | 48.6% | 46.6% | +1.9 pts | not significant |
| Price crosses above EMA200 | 2,175 | 52.0% | 50.3% | +1.7 pts | not significant |
| Price crosses below EMA200 | 2,174 | 49.1% | 47.7% | +1.4 pts | not significant |
| EMA 9/21 bull cross | 2,440 | 50.5% | 51.0% | -0.5 pts | not significant |
| Golden cross (EMA 50/200) | 334 | 48.2% | 48.4% | -0.2 pts | not significant |
Not one of the six reached statistical significance. The golden cross and death cross are the worst offenders on sample size - 334 and 333 occurrences respectively across 28 instruments and sixteen years, because a 50/200 crossover is by construction a rare event. Any win rate quoted for the golden cross without that sample size attached is not a measurement, it is an anecdote.
Look at the EMA 9/21 rows for the more useful lesson. The bull cross won 50.5% of its trades, which reads like a positive result, but a random long with the same stop won 51.0% of the same setups - the crossover subtracted value. The bear cross won less often (48.6%) yet beat its random control by 1.9 points. Raw win rate tells you about your stop placement; only the comparison tells you about the signal. The full indicator win-rate study has all fourteen signals across both timeframes and both targets.
Test it before you trust it
Every indicator lags, because it is built from prices that have already printed. Add it to the chart in the simulator, trade the same setup with and without it across a large sample, and keep it only if it genuinely raises your expectancy - not because the signal looks convincing in hindsight.
Moving Averages FAQ
What is the difference between SMA and EMA?
A simple moving average (SMA) weights every candle in its window equally, so it is smooth but slow to react. An exponential moving average (EMA) gives more weight to recent candles, so it reacts faster to new price but is choppier. Traders use the EMA when responsiveness matters and the SMA when they want a steadier trend line.
Which moving average period is best?
There is no universally best period - it depends on your timeframe and goal. Short periods like 9 or 20 track price closely for entries; long periods like 100 or 200 define the major trend. Popular choices are common because many traders watch them, but you should backtest the periods on your own pairs rather than assume.
Do moving average crossovers work?
Crossovers work well in strong, sustained trends and poorly in ranges, where they whipsaw. Because a moving average lags price, a crossover confirms a move that has already started. Treat it as a trend filter combined with price action and a backtest, not as a standalone mechanical signal.