The mean reversion concept we use at Vtrender works on the two standard deviation concept stating clearly that prices have a less than 5 % chance of staying below the 2 SD price.
We track this intra day in our charts, but the concept works on all time frames and is a much better indication of oversold/ overbought conditions than most oscillators. The only difference is that the vwap module of 2SD takes into consideration Volume as well unlike Price used in most oscillators.
Have a look :
Focus on the blue lines and you will note that the odds of bouncing higher from the lower blue lines are indeed very high.
The statistical probability is 95 %.