# How is stock market volatility calculated?

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## Top best answers to the question Â«How is stock market volatility calculatedÂ»

Volatility is often calculated **using variance and standard deviation**. The standard deviation is the square root of the variance. For simplicity, let's assume we have monthly stock closing prices of $1 through $10â€¦ Calculate the difference between each data value and the mean.

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Traditional Measure of Volatility Most investors know that standard deviation is the typical statistic used to measure volatility. Standard deviation is simply defined as the square root of the...

Volatility is the up-and-down change in the price or value of an individual stock or the overall market during a given period of time. Volatility can be measured by comparing current or expected returns against the stock or marketâ€™s mean (average), and typically represents a large positive or negative change.

Calculate the volatility. The volatility is calculated as the square root of the variance, S. This can be calculated as V=sqrt(S). This "square root" measures the deviation of a set of returns (perhaps daily, weekly or monthly returns) from their mean. It is also called the Root Mean Square, or RMS, of the deviations from the mean return.

However, historical volatility is an annualized figure, so to convert the daily standard deviation calculated above into a usable metric, it must be multiplied by an annualization factor based on...

The formula for the volatility of a particular stock can be derived by using the following steps: Firstly, gather daily stock price and then determine the mean of the stock price. Let us assume the daily stock price on... Next, compute the difference between each dayâ€™s stock price and the mean ...

Volatility is determined either by using the standard deviation or beta Beta The beta (Î˛) of an investment security (i.e. a stock) is a measurement of its volatility of returns relative to the entire market. It is used as a measure of risk and is an integral part of the Capital Asset Pricing Model (CAPM).

Video in excel showing how to calculate historical volatility of a stock or underlying security for which you have historical data.

Now to calculate stock market volatility using the standard deviation, you could look at this process for a broad index such as the S&P 500. Typically, we also would use daily returns rather than annual returns. Taking the standard deviation of daily returns is a very common way to measure risk and volatility.

The following steps can be followed when calculating volatility through determining the standard deviation over time: Collect the historical prices for the asset. Compute the expected price (mean) of the historical prices. Work out the difference between the average price and each price in the series.