Bollinger band mean reversion

Technical Analysis
1

Just to understand better I would have two questions: 

  1. if I set a Bollinger band with lookback of 5 and +-0.5 std, Will I have a correspondant situation in normal Bollinger graphic instrument with paramenters lenght=5 and mul=0.5?I mean when I set the Bollinger in my trading software I have two parameters Lenght and Mul, is the lookback the correspondant of lenght and the std the correspondant of mul? 
  2. Is not to small 5 as lookback? Or is there a way to determine the best lookback parameter?
Thank a lot
2

Thanks for your query. 

  1. Yes, most tools name the look back used to calculate the SME as "length" and the multiplier of the standard deviation to create the upper and lower band as "mul" 


  2. It depends on the instrument you are trading. You can take the multiplier of the half-life of the security as the look back. 
3

Standard deviation of 5 points is not meaningful.

 

4

Thanks for your inputs. The upper band is tpically kept at two standard deviations above the moving average and the lower band two standard deviations below it.