There are 4 steps to confirm a W-Bottom with BBs. First, a reaction low forms. This low is usually, but not always, below the lower band. Second, there's a bounce towards the middle band. Third, there is a new or equal price low in the stock. This low holds above the lower band. The ability to hold above the lower band show less weakness on the last decline. Fourth, the pattern is confirmed with a strong move off the second low and a resistance break.
M-Top