In capital markets, volume, or trading volume, is the amount (total number) of a security (or a given set of securities, or an entire market) that was traded during a given period of time.
The volume of trade is a measure of the market's activity and liquidity during a set period of time.
News about a company's financial status, products, or plans, whether positive or negative, will usually result in a temporary increase in the trade volume of its stock.
Shifts in trade volume can make observed price movements more significant.
[3] For institutional investors who wish to sell a large number of shares of a certain stock, lower liquidity will force them to sell the stock slowly over a longer period of time, to avoid losses due to slippage.