The average true range (ATR) is a price volatility indicator showing the average price variation of assets within a given time period. Investors/Traders can use the indicator to determine the best time for trading. The average true range also takes into account the gaps in the movement of price.

The best average true range period to trade with is 10. PTG has found out through extensive research that 10 sessions or 10 periods is the perfect number to measure the volatility.

Further study can be found at this link: ATR Stop (Average True Range)