The Standard Deviation Indicator MT5 is a popular and free forex indicator that is used to measure the volatility of a currency pair. The indicator calculates the average price of a currency pair and then measures the deviation of the price from the average. This allows traders to get a better understanding of price movements and identify potential entry and exit points. The Standard Deviation Indicator MT5 is an essential tool for any forex trader and can be used to help traders make better trading decisions.