In the chapter on 'Market Sentiment', it's said that when volume is way up (the example was five times average) and the price is trending down, that's a strong signal to buck the trend and buy.

This is actually in line with my own 'education' so far. When there is 'blood on the floor' or the stock is beaten down, that can be a good time to closely examine if the stock is oversold and due to bounce back. That's actually the story of the first stock that interested me, Dreamworks Animation. Now at this writing, this has not been a wildly successful move (buying in at $23), but it still feels like it holds some potential.

The topic of 'on-balance volume' (OBV) seems promising. It's a

'running (cumulative) total of volume, calculated by adding the volume on day's the price is higher than the day before and subtracting the volume on days the price is lower than the day before.'

Joe Granville is credited with codifying the concept. I like (obviously) that it can have a tendency to predict trend reversals.

I'm thinking that any charting software I choose to buy should have this OBV feature.