Exponential Moving Average
A moving average that weights recent prices more heavily than older ones.
Also called: ema
In plain language
An EMA applies exponentially decaying weights, so the most recent closes matter most and old data fades rather than dropping out abruptly.
The practical effect is that it turns faster than a simple moving average of the same length. That is an advantage in a trending market and a liability in a choppy one.
Common lengths — 9, 21, 50, 200 — are conventions, not discoveries. Their usefulness comes partly from how many people watch them.
Why it matters
The choice between EMA and SMA is really a choice about responsiveness versus false signals. Neither is better in the abstract; they suit different conditions.
Common mistakes
- Assuming a faster average is a better average.
- Switching between EMA and SMA depending on which currently supports the position you already hold.
Keep exploring
These concepts are connected. Understanding one usually makes the next one easier.
The average price over a set number of periods, recalculated as each new period closes.
A momentum indicator built from the difference between two exponential moving averages.
A sustained directional bias in price, built from a repeating pattern of highs and lows.
When price makes a new extreme but the indicator does not, suggesting momentum is fading.
A period where price moves sideways in a narrow range without clear direction.