Moving Averages Guide: SMA, EMA, WMA and How to Use Them

A moving average is the simplest possible smoothing filter applied to a price time series. Take the last N closes, average them, plot the result against the most recent bar, slide the window forward one bar, repeat. The output is a line that shows the central tendency of price over the chosen window.

This is genuinely useful for three reasons: it reveals the underlying trend that short-term noise conceals, it gives a single objective line that multiple traders can reference (creating self-fulfilling S/R), and it is trivially cheap to compute. What it is not: a prediction. A moving average lags price by approximately N/2 bars – by definition, the centre of mass of the window is in the past. Every MA strategy ever devised pays for noise reduction with that lag.

There are dozens of variants. Four cover 98 % of practical use.

• Simple Moving Average (SMA) – unweighted average of the last N closes. Maximum smoothing, maximum lag. The 200-day SMA on an equity index is the canonical long-term trend filter.
• Exponential Moving Average (EMA) – recursive filter where each new bar contributes a fraction α = 2/(N+1) of the difference between price and the prior EMA. Faster-reacting than SMA, but noisier. EMA is the default on most intraday strategies.
• Weighted Moving Average (WMA) – linear weights (N for the latest bar, N-1 for the prior, down to 1 for the oldest). Intermediate lag and responsiveness.
• Hull Moving Average (HMA) – designed by Alan Hull (2005) to reduce lag while keeping smoothness. Built from a blend of WMAs and a square-root-period final WMA. Visually the smoothest-looking fast MA; used heavily in intraday systems.

The choice of MA type is second-order. The period you pick matters more than whether it is simple or exponential.

Nothing magical about these numbers – they are Schelling points. Once enough market participants watch the same levels, price behaves as if those levels matter, and for all practical purposes they do. The three standard periods:

• 20-period – roughly a trading month on the daily chart. The 20-EMA is the canonical short-term trend filter. On a 1-hour chart, the 20-EMA approximates the session-and-a-half trend.
• 50-period – roughly 2½ trading months. The 50-SMA is the most-watched intermediate trend line in US equities; price respecting it is a sign of a healthy uptrend.
• 200-period – roughly a trading year. The 200-SMA is the single most-referenced long-term trend line. Stocks above it tend to be in bull regimes; below, in bear regimes. Faber (2007) showed a simple "own SPY above 200-day SMA, cash below" rule would have delivered equity-like returns with half the volatility, 1900–2012.

On intraday timeframes the analogues are 9 / 21 / 50 on 5-minute charts, or VWAP as an intraday long-term anchor.

The simplest and most robust use: trade only in the direction of the longer MA's slope.

• Long trend = price above a rising long MA (e.g., 200-SMA).
• Short trend = price below a falling long MA.
• No trend = long MA flat, price crisscrossing it repeatedly. Stand down.

This single filter eliminates the majority of counter-trend trades that turn small losers into account-killers. On an evaluation, applying a "only long when 4H-chart price is above 50-EMA and 50-EMA is sloping up" rule to any entry strategy typically cuts drawdown by 20–40 %.

In a trending market, price often pulls back to a MA and bounces. The 20-EMA and 50-EMA act as "dynamic" support in an uptrend and resistance in a downtrend. The workflow:

1. Confirm a trend on the higher timeframe (e.g., daily price above 200-SMA, sloping up).
2. Wait for a pullback to a key MA on the lower timeframe.
3. Look for a candlestick pattern or a higher-low structure at the MA as the entry trigger.
4. Place the stop just beyond the MA (below the swing low for a long).

This "pullback-to-MA" setup is the bread and butter of mechanical trend-following CTAs and discretionary traders alike. See the candlestick patterns guide for entry triggers at MA levels.

A moving-average crossover system buys when a fast MA crosses above a slow MA, and sells when it crosses back below. The most famous:

• Golden Cross – 50-SMA crosses above 200-SMA. Widely reported in financial media; associated with the start of a bull market.
• Death Cross – mirror of the above. 50-SMA crosses below 200-SMA.
• Fast/Slow EMA crosses – e.g., 9/21 on intraday charts, 12/26 as the basis of MACD.

The academic record on crossover strategies is mixed. Brock, Lakonishok & LeBaron (1992) documented statistically significant excess returns from simple crossover rules on the Dow from 1897 to 1986. However, Bajgrowicz & Scaillet (2012) and subsequent work suggest the effect has substantially decayed post-2000 as algo traders arbitrage it away. On most modern liquid instruments, a bare crossover is not a profitable standalone system – but it remains a useful component of a multi-filter strategy.

Moving averages work in trends. They fail – systematically, predictably – in three regimes:

• Range-bound markets. Price oscillates around a flat MA; every crossover is a whipsaw. This is the majority of most markets most of the time. Use ADX < 20 or a narrow Bollinger band squeeze as a filter to stand down.
• Gaps and single large candles. News events and overnight gaps throw price well beyond the MA in one bar. The MA lags badly, giving late signals.
• Regime shifts. When a multi-year trend ends, the 200-SMA breaks and then stays broken for weeks while the new regime forms. The transition period is poison for MA-based systems.

The correct response is not to pick a "better" MA period but to pair the MA with a trend-strength filter (ADX, vol-adjusted range) and stand aside when the filter says no trend.

Three simple, robust ways to use MAs on a prop-firm account:

1. The 200-SMA regime filter. Take long setups only when the instrument's daily price is above the 200-SMA; take short setups only when below. This one filter removes more bad trades than any other single rule.
2. The 9/21 EMA intraday ribbon. On 5-minute charts, plot the 9-EMA and 21-EMA. Only take long scalps when 9 is above 21 and both are sloping up; mirror for shorts. Exits on a close across the 9.
3. The pullback-to-20 swing setup. On the 4-hour, wait for price to pull back to the 20-EMA in a confirmed trend, wait for a bullish reversal candle (hammer, bullish engulfing), enter with a stop below the pullback low, target 2R.