Dear All,

Hope my msg finds you very well.

I have a panel data 252 observations (daily ) (id, date,prc,ret and shrout) noting that ret=daily % change.
Please , how i can generate/ calculate an annualized standard deviation .
Please find below an example of data structure .

Many thanks in advance
gvkey date prc ret shrout
1005 2-Jan-81 26.375 0.004762 906
1005 5-Jan-81 26.875 0.018957 906
1005 6-Jan-81 26 -0.03256 906
1005 7-Jan-81 23.875 -0.08173 906
1005 8-Jan-81 22.875 -0.04188 906
1005 9-Jan-81 22.5 -0.01639 906
1005 12-Jan-81 22.5 0 906
1005 13-Jan-81 22.375 -0.00556 906
1005 14-Jan-81 22.25 -0.00559 906
1005 15-Jan-81 23.5 0.05618 906
1005 16-Jan-81 25 0.06383 906
1005 19-Jan-81 24.625 -0.015 906
1005 20-Jan-81 24.25 -0.01523 906
1005 21-Jan-81 24.375 0.005155 906
1005 22-Jan-81 24.625 0.010256 906
1005 23-Jan-81 24.75 0.005076 906
1005 26-Jan-81 24.125 -0.02525 906
1005 27-Jan-81 24.125 0 906
1005 28-Jan-81 24 -0.00518 906
1005 29-Jan-81 23.75 -0.01042 906
1005 30-Jan-81 24 0.010526 906
1005 2-Feb-81 17.875 -0.06901 1133
1005 3-Feb-81 18.75 0.048951 1133
1005 4-Feb-81 19.375 0.033333 1133
1005 5-Feb-81 19.75 0.019355 1133
1005 6-Feb-81 18.625 -0.05696 1133