The phrase "declining volume" means that the amount or quantity of something is decreasing over time.
Sentences with «declining volume»
However, advancing volume topped declining volume on both exchanges. (morpheustrading.com)
But those gains were offset by declining volume on other exchanges. (marketvoice.fia.org)
The decline in price action accompanied by higher volume and higher declining volume suggests that institutions continue to place selling pressure on the market. (morpheustrading.com)