Indicator is based on calculation of two standard deviations and result is ratio between them. 

As single indicator it doesnt show direction of price, it only show high activity area. I recommend to combine it with other indicators or price action.

Signal ideas:

• When indicator cross treshold line and slope change back down.
• When indicator cross treshold line up.
• When indicator cross treshold line down.
• When indicator is bellow treshold line its possible trending market.