The Exponential Moving Average, commonly referred to as EMA, is a technical analysis indicator used to identify trends in asset prices by smoothing out the price data over a specified period of time. The EMA places greater weight on more recent prices, making it more responsive to short-term price changes than a simple moving average.
The EMA is calculated using a formula that takes into account the current price, the previous EMA value, and a smoothing factor. The smoothing factor, which is a value between 0 and 1, determines the weight given to the current price relative to the previous EMA value.
Example:
Let's say you want to calculate the 10-day EMA for a stock. The first step is to calculate the simple moving average (SMA) for the first 10 days of the data series. Let's assume that the closing prices for the first 10 days are as follows: Day 1: $20, Day 2: $22, Day 3: $25, Day 4: $24, Day 5: $23, Day 6: $22, Day 7: $20, Day 8: $21, Day 9: $23, Day 10: $25.
To calculate the SMA, you would add up the closing prices for the first 10 days and divide by 10:
SMA = (20 + 22 + 25 + 24 + 23 + 22 + 20 + 21 + 23 + 25) / 10 = $22.5.
Next, you would calculate the smoothing factor, which is typically calculated as follows:
Smoothing factor = (2 / (n + 1))
where n is the number of periods in the EMA, in this case, 10.
Smoothing factor = (2 / (10 + 1)) = 0.1818.
Next, you would use the following formula to calculate the first EMA value:
EMA1 = SMA.
In this example, EMA1 would be $22.5.
To calculate subsequent EMA values, you would use the following formula:
EMA = (Closing price - Previous EMA) x Smoothing factor + Previous EMA.
Let's assume that the closing price for Day 11 is $27, and the previous EMA value is $24.54. The calculation for the 11th day's EMA would be as follows:
EMA = ($27 - $24.54) x 0.1818 + $24.54 = $25.89.
So the 10-day EMA for the stock on Day 11 is $25.89. This process would be repeated for each subsequent day in the data series.