Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Somer G. Anderson is CPA, doctor of ...

Marshall Hargrave is a stock analyst and writer with 10+ years of experience covering stocks and markets, as well as analyzing and valuing companies. Dr. JeFreda R. Brown is a financial consultant, ...

Standard deviation and variance are two basic mathematical concepts that have an important place in various parts of the financial sector, from accounting to economics to investing. Both measure the ...

Standard deviation is a metric that shows the variability of a security’s returns over time. It can be used to gauge volatility based on past performance and compare a future return to past returns.