Volatility is a measure of how the price of an asset – be it a stock, an option or a fund - changes. Volatility tracks how much the price moves and also how fast it changes. Beta is a commonly used statistical measure that represents volatility, and the higher beta is, the greater the risk. There’s usually a reference index such as the S&P 500 and if a stock perfectly tracks the index, it is said to have a beta of 1.0. If it changes more than the index, be it on the up or downside, it is a high beta stock. For example, a stock with a beta of 1.5 means that historically, it has moved 150% for every 100% move in the benchmark index. Mutual funds nowadays provide free volatility measures so you can get a good feel for how stable the fund is year in and year out.