EMA

Exponential moving average — trend, reacts faster than SMA.

The exponential moving average (EMA) is a recursive average that updates by blending today's close into yesterday's EMA via a smoothing factor α = 2 / (N + 1). Older observations decay exponentially rather than dropping off a fixed window, so the EMA reacts faster to new price action than the equivalent-length SMA.

EMAs are the building block for many other indicators: MACD is the difference of two EMAs, the signal line is an EMA of MACD, and many strategies use a 9 / 21 / 50 EMA stack to gauge short- vs. medium-term trend.

The trade-off versus SMA: faster response in trending markets, but more whipsaws in chop. The smoothing factor α is unitless — the same EMA(20) on 1-minute bars and on daily bars uses the same recursion.

EMA_t = α · P_t + (1 - α) · EMA_{t-1},  where  α = 2 / (N + 1)

Lisez la définition complète de Exponential moving average (EMA) dans le glossaire →