How to Measure Volatility of a Stock

Create a spreadsheet to compile and calculate stock price information. Make a separate page in the spreadsheet for each stock you are going to track to keep things simple and organized until you get accustomed to keeping and reading this type of data. For each stock make a column for historical stock prices and another for daily stock prices.
Make a list of the stocks you have holdings in currently and those that you are considering investing in. Write down stock names, trading symbols and stock prices with dates. Access historical stock price data and copy the information directly in to the spreadsheet you created.
Enter all historical information in to the spreadsheet. At a minimum you will need one month worth of daily stock prices to get started but for better results six months of historical stock price data is good.
Calculate what is known as the average closing price. This is done by finding the average of the stock price based on a period of time. Taking the six-month window of historical data as an example, you would find the average price of a stock over six months by adding all of the daily prices from the six-month range and dividing that number by 183. A different example would be for a 20-day period; add all 20 daily numbers and divide by 20 for the simple average.
Take the average closing price and calculate the difference between that average and the actual closing price. If you are using a spreadsheet you would create a third column for this information. This number is what is known as the deviation.
Square the deviation number and then add together all of the deviations for the time period that you are tracking. Then you take that sum of the squared deviations and divide that number by the time period you are tracking. For example, in the 6-month example you would divide the sum of all squared deviations by 183.
Take the square root of the last number calculated and you are left with the standard deviation. A higher standard deviation number means higher stock price volatility which then implies more pricing swings and movement, which is attractive to higher risk investors.

How to Buy Wells Fargo Preferred Stock (6 Steps)

Compare the different types of preferred stock available. Wells Fargo Capital has six offerings. They include Non-Cumulative Convertibles (CUSIP: 949746804), Non-Cumulative Perpetual (two offerings; CUSIP: 949746PM7 and 949746879), Wells Fargo Preferred Funding Corp (CUSIP: 92977V206), Fixed Rate Cumulative Perpetual (No CUSIP) and Dividend Equalization Preferred (CUSIP: 949746887).
Compare callable dates. A call date refers to the date the company can 'call back' or pay you back for the securities. Convertibles have a call option embedded as a feature and the fixed rate cumulative securities are also callable at any time. All others have call dates ranging from March 15, 2018, to Dec. 31, 2022.
Compare coupons. The coupon is the amount you will receive in interest for buying the bond. Coupons are both fixed or floating, and range from 5 percent to 9 percent or more depending on the associated index.
Compare coupon payment dates. Payment dates can range from twice a year to four times a year. Choose an offering that best fits your income needs.
Compare final maturities. All of Wells Fargo's preferred stock are perpetual, which means they have no final maturity date.
Make a purchase through your broker, online broker or contact Wells Fargo Capital directly. You will need the CUSIP number provided in Step 1. This number contains all the information the broker or Wells Fargo representative needs. You will also need to stipulate the number of shares you wish to purchase. Divide the amount you would like to invest by the current price of the stock (see Resources).

How to Calculate Stock Price Volatility

Gather stock price information. You will need at least a month of daily stock price data. However, you will get the best results by using at least six months of data. If you don't know how to do this, go to Yahoo! Finance, input the stock's ticker symbol into 'Get Quotes,' and click on 'Historical Prices.' Copy and paste this information directly into a spreadsheet. Label Column A to represent historical stock price trading dates and Column B to show daily closing stock prices.
Find the average price over the length of time you chose. For example, if you pulled out six months of information, take the average price over 183 days. This can be set up as the AVERAGE function or by taking the sum of all daily prices (Column B) and dividing by 183.
Calculate the difference between the daily price (Column B) and the average over the range of data. If you're using a spreadsheet, create a Column C, which will refer to this difference, by subtracting Column B from the average. Copy and paste this function down the length of the data on your spreadsheet.
Square the difference. Create a Column D into which you put the square of Column C. You do this by multiplying the Column C value by itself. Now find the sum of Column D and divide by your days range (183 days for 6 months of data). This is called the variance.
Take the square root of the variance, using the SQRT function. This result gives the stock's standard deviation for the entire sample of price data. In the investor world, this number represents a measure of stock-price volatility.
Check your results with a historical-volatility calculator. Use the same data referred to in the calculations above. See Resources for a link to an historical-volatility calculator.