Let the variance of returns for a share per month be ##\sigma_\text{monthly}^2##.
What is the formula for the variance of the share's returns per year ##(\sigma_\text{yearly}^2)##?
Assume that returns are independently and identically distributed (iid) so they have zero auto correlation, meaning that if the return was higher than average today, it does not indicate that the return tomorrow will be higher or lower than average.
Question 308 risk, standard deviation, variance, no explanation
A stock's standard deviation of returns is expected to be:
 0.09 per month for the first 5 months;
 0.14 per month for the next 7 months.
What is the expected standard deviation of the stock per year ##(\sigma_\text{annual})##?
Assume that returns are independently and identically distributed (iid) and therefore have zero autocorrelation.
Question 559 variance, standard deviation, covariance, correlation
Which of the following statements about standard statistical mathematics notation is NOT correct?
The standard deviation and variance of a stock's annual returns are calculated over a number of years. The units of the returns are percent per annum ##(\% pa)##.
What are the units of the standard deviation ##(\sigma)## and variance ##(\sigma^2)## of returns respectively?
Hint: Visit Wikipedia to understand the difference between percentage points ##(\text{pp})## and percent ##(\%)##.
Question 988 variance, covariance, beta, CAPM, risk, no explanation
Price Data Time Series  
Sourced from Yahoo Finance Historical Price Data  
Date  S&P500 Index (^GSPC)  Apple (AAPL)  
Open  High  Low  Close  Adj close  Open  High  Low  Close  Adj close  
2007, Wed 3 Jan  1418  1429  1408  1417  1417  12.33  12.37  11.7  11.97  10.42  
2008, Wed 2 Jan  1468  1472  1442  1447  1447  28.47  28.61  27.51  27.83  24.22  
2009, Fri 2 Jan  903  935  899  932  932  12.27  13.01  12.17  12.96  11.28  
2010, Mon 4 Jan  1117  1134  1117  1133  1133  30.49  30.64  30.34  30.57  26.6  
Source: Yahoo Finance.  
Which of the following statements about the above table which is used to calculate Apple's equity beta is NOT correct?
Question 1005 variance, covariance, beta, CAPM, risk, no explanation
Price Data Time Series  
Sourced from Yahoo Finance Historical Price Data  
Date  Adjusted close  
S&P500 Index (^GSPC) 
Tesla (TSLA) 

2017, Fri 29 Dec  2673.61  62.27 
2018, Mon 31 Dec  2506.85  66.56 
2019, Tue 31 Dec  3230.78  83.67 
2020, Tue 31 Dec  3756.07  705.67 
Source: Yahoo Finance.  
Which of the following statements about the above table which is used to calculate Tesla's equity beta is NOT correct? Over the last 4 years the historical: