This what I just read on Stockscores and it is very relevent here with respect to volume. (Stockscores initiated a play in AMC on Friday based on the breakout supported with abnormal Volume activity. It was also mentioned that a possible explanation on why the sell off at the end of day was mostly overhead resistence by those who have held this stock looking for the right time to exit.)

10. Abnormal Activity Indicates Something Out of the Ordinary is Happening
To beat the market requires you trade on information that is not already well disseminated. This can be achieved with in depth research or inside knowledge. Within every company there are some people with this kind of information and they act in the market, leaving a trail to follow. New information is often highlighted by abnormal trading activity