Equity Risk

Equity risk is the risk that one's investments will depreciate because of stock market dynamics causing one to lose money.

The measure of risk used in the equity markets is typically the standard deviation of a security's price over a number of periods.

The standard deviation will delineate the normal fluctuations one can expect in that particular security above and below the mean, or average.

However, since most investors would not consider fluctuations above the average return as "risk", some economists prefer other means of measuring it.