AThis volume wave, in the middle of a trading range (this is not marked on the chart), is high and shows an abundance of selling pressure.
BHere the price is a bit lower than the earlier wave but the volume is a little lower too. Selling pressure has diminished. But, it's too early to enter a trade because the volume wave is still pretty high.
CAfter price increased, the first reaction occured on significantly lower volume. This is the first buying opportunity.
DPrice is even higher while the volume wave is the lowest in this series. This is also an excellent buying opportunity because it shows that there is very little selling pressure left.