Volume is a measure of participant agreement.
When there is agreement to voume is high.
When there is disagreement the volume is low.
Participants are owners of market interests and market instruments. Participants are also people with cash. Owners play the "old" role and cash plays the "new" role.
What you are seeing is "I'm not going to sell at these prices" and "I'm not going to buy at these prices" from the opposite sides of the market.
For those that time the market, they are making a lot of money these days. You can tell by looking at "market" orders after the fact.
If you want to see the screw up traders via volume look at bars around 4:00 EST when the maintenance margin changes from day to not day.
If you want to see how "settlement" went on any particular day, check the settlement volume right after lunch.
The sentiment is controlled by the minority. This is the direction the market is moving in.
As you may or may not learn, volume leads price. This is a result of deductive reasoning. Inductive reasoning, incorrectly, leads to the CW views on volume and price. CW is the majority, fortunately.