I have the average variance of a stock's daily return over a year and I want to know whether or not I can times this number by 252 (number of trading days in a year) to find the yearly variance. My prediction is that I can because you can add the variances of two independent random variables and one could argue that the return of the stock on one day does not affect the return on the next (in theory). Am I correct? If not how can I get the yearly variance from this data?
EDIT: another reason I think I'm correct is that you can multiply the mean return and get the average return for the year so why not variance too.