Numbers on a stock exchange illustrate the health of individual stocks and the entire stock market at a glance. Numbers tell whether wealth was created or destroyed in a given trading session and how eager investors were to trade shares.
Volume represents the number of shares that exchange hands in a trading session. If, for example, the volume on Apple's stock is 25 million, this means that 25 million Apple shares have been bought and sold in the most recent trading session, according to Nasdaq. Abnormal volume patterns may indicate a company is on the brink of an important event.
The Dow Jones Industrial Average is a composite value of 30 of the largest stocks. Its underlying value rises and falls based on buying activity in the stock market. The S&P 500 is structured similarly except its composite value is based on 500 companies across leading industries. Once a stock is added to an index, it can be replaced if it does not maintain certain criteria.
A stock trades based on a dollar-per-share price that changes direction based on investor demand. A stock price is the amount an investor must pay to purchase each share. The first trading value assigned to a stock is set before its initial public offering. It is based on the price of similar companies in the stock market and the economic environment at the time of the offering.
The corresponding number next to an index value or stock value is the change, either upward or downward, for the session. The point change is relevant as it illustrates sentiment surrounding a stock or index in a day. However, a percentage move can be even more compelling, especially for indexes. A 20-point move in an index valued at 10,000 may not move the meter, but a 2 percent move will.
There are many statistics involved in the stock market and various ways to communicate a notable event. For instance, stocks set historical records, but they also set records based on performance within a year. In December 2009, the Dow Jones Industrial Average was on pace to close at or near its highest level of the year, despite the fact that it was not a historical best for the index, according to CNBC.