Volatility

What Is Volatility?

Volatility describes the degree to which the price of a security, index, or other asset rises and falls over time. A stock whose price moves in large, frequent jumps is considered highly volatile, while one whose price changes gradually and within a narrow range is considered low in volatility. Volatility says nothing about whether prices are heading up or down. It only measures the size and pace of the movement.

In finance, volatility is most often measured as the standard deviation of an asset's returns over a set period. Standard deviation shows how far individual returns tend to fall from their average. Analysts usually annualize the figure so that results from different time frames can be compared.

How Volatility Is Measured

Investors commonly look at two types of volatility. Historical volatility is calculated from past price data, such as the daily returns over the last few months. Implied volatility is derived from the prices of options contracts and reflects the market's expectations for future movement. Implied volatility is often watched as a gauge of investor uncertainty, and it tends to rise during periods of stress.

Why Volatility Matters to Investors

Volatility is one of the main ways investors judge risk. A more volatile holding may produce larger gains, but it can also produce larger losses over short periods, which can be difficult to tolerate. Volatility also affects the price of options, since options tend to cost more when the underlying asset is expected to move a lot. Many portfolio managers track volatility at the portfolio level to understand how much the overall value of their holdings might fluctuate.

Volatility is not the same as a permanent loss of capital. Prices can swing widely while the underlying business remains sound, and a low-volatility asset can still lose value over time. Understanding volatility helps investors interpret price charts and set expectations, but it is only one part of evaluating an investment.