Quote from dbphoenix:
Since nobody's bothering to answer this, I'll get you started.
There are never more sellers than buyers. Nor more buyers than sellers. Every transaction requires both. If price is falling, the buyers are there. Otherwise, there would be no transaction. However, they are not willing to pay what the sellers are asking. Therefore, the price must be lowered.
As to the volume, what else would you expect? Stronger up volume to R, then stronger down volume to S. If the volumes were more equivalent, the price would be more likely to drift sideways in a coil. What you're really wondering is whether or not you can predict what's going to happen once you get to S or R, and the answer is no. The best you can do is provide yourself with reversal, breakout, and retracement strategies, then employ whatever's appropriate for whatever opportunity the market provides. You may at some point be able to assign probabilities to a breakout vs a reversal, but you needn't concern yourself with that in order to trade.