The Volume Indicators by Bruce R. Faber
In spite of its importance, much less is written about volume than about price. Here's an introduction on the subject for the novices and a refresher for the veterans.
To technical analysis, volume is as important as price. Some analysts would even claim that volume is more
important of the two. But price without volume is like Standard without Poor's; by itself, price represents only half of the necessary information. At the very least, what volume is doing in relation to price should always be taken into consideration when making trading decisions.
On most charts, the daily volume is depicted by a vertical line/bar directly below the corresponding price
point, bar or candlestick. In Figure 1, which shows Intel Corp. [INTC], volume lines can be seen at the bottom. The relative height of the volume line is usually compared only with the other volume bars within the
period covered by that particular chart.