Of course, one must be careful not to focus so much on the form that he overlooks the substance:
The first standard deviation correlates to the value area. This is a high volume area. It shows price acceptance confirmed by use: a fair price area.
The third standard deviation correlates to a price excess. This is a low volume area. It shows price rejection: an unfair price area.
These low volume price areas are key reference points because they can contain the range. When the market reaches these potential parameters, it can only do one of two things: trade through or reverse direction.