paul
good example.
mmm, in general I see it slightly differently if you start from two facts: 1. For every sale there must be a buy - thus buys and sells are always equal and there can't be a preponderance on one side or the other. 2. You can only sell at a price if someone wants to buy at that price (forgetting spread) and vice versa.
There can, of course, be a preponderance of buyers or sellers waiting in the wings, either because of new participants arriving on one side or because of numbers on one side reducing (or because the price isn't yet right). By the time a volume bar prints it's history and we're only interested in it to give us clues about who's waiting in the wings.
So, in your down trend, sellers continually need to offer down to attract buyers and it's maybe a clue that more sellers than buyers wait in the wings. When there is large volume, more of those sellers are able to offload because more willing buyers have arrived and that's maybe a clue that there may soon be more buyers than sellers in the wings.
Does that sound logical? I wonder if it's right
jon