Mean reversion strategy explained simply

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In short

Mean reversion means a return to the mean. The strategy assumes that strong swings often fade again. It measures a moving average and a band around it. When price closes outside the band, it opens a counter position.

The target is the middle. In calm, swinging markets that fits well. When the stretch turns into a trend, every counter position is wrong, and then the stop is what counts.

The strategy as a schematic

A drawn price path, no market data. First the case where the rule works, then the same routine when it fails.

Closed: ±0 pips
Open: –
Open volume: –

Schematic, no market data: a drawn price path, results in pips weighted to 0.10 lots. Not a backtest and no statement about any real EA.

How the strategy trades

Calculate a mean (e.g. 20 candles) and a band around it, for example two standard deviations (Bollinger bands).
Close above the upper band: sell. Below the lower band: buy.
The target is the middle line.
The stop sits a fixed distance beyond the entry.
One position at a time, no adding.

Where the risk sits

With a stop the risk per trade is capped. Without one, mean reversion quickly turns into a grid, because you add when the stretch continues.

The strategy deliberately trades against the current move. When a trend starts, every signal is against it, and several stops follow one another.

Wins are limited by the distance to the middle, losses by the stop. If the stop is much larger than the usual distance to the middle, the strategy needs many winners.

When it works, when it fails

Tends to work when …

Markets that swing around a mean without a clear direction.
Short stretches that are quickly unwound.

Tends to fail when …

The start of a trend: price stays outside the band and keeps going.
News that creates a new price level.
Sharply rising volatility that widens the band and delays the signals.

How to recognise it in an EA

Traces in the trade log of a live account, whatever the vendor calls the EA.

Entries against the last move, often after several candles in one direction.
Exits close to an average, holding times of hours.
Medium to high hit rate, wins and losses of similar size.
Losing phases coincide with strong trending months.

Typical settings

Setting	Typical	Effect
Length of the mean	14–50 candles	What counts as normal.
Band width	2–2.5 standard deviations	Wider = rarer but stronger stretches.
Stop	fixed distance or ATR multiple	Without a stop it becomes a grid.
Target	middle line or opposite band	The middle line is hit more often.
Trend filter	e.g. no trades when the average is steep	Avoids signals against strong trends.

Common ranges from EA manuals and set files, not a recommendation.

EAs in our tests built this way

10 graded EAs from our tests carry this design. Grade on a 0 to 10 scale, one formula for all; no live figures.

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Frequently asked questions

What is the difference between mean reversion and range trading?

Both trade against stretches. Mean reversion measures the stretch against a moving average that moves with the market. Range trading uses fixed price zones marked in advance.

Why does mean reversion fail in trends?

Because a trend consists of many stretches in the same direction. The strategy sells each of them and is stopped out every time.

Is a grid EA a mean reversion strategy?

At its core, yes, a grid also bets on price returning. The difference is the risk: mean reversion with a stop takes the loss per trade, a grid adds positions and carries the risk in the basket.

Video: the strategy in under a minute

The same animation as a video with subtitles, for those who prefer to watch.

Mean reversion explained simply