The Breadth of the Market

C

The "breadth" of the market is used to refer to the amount of activity spread across all the instruments traded (as against the activity being concentrated on a few stocks or instruments). One measure of this breadth is given by the number of price increases and decreases over the previous day. The difference between the two not only serves as a partial explanation of the change in market direction but also indicates whether a rise or fall in the market is pervasive or influenced by a concentrated group of traded securities.