Yearly Standard deviation for daily stock return

[Fer_]

Hello Everyone. 

I want to calculate standard deviation of the firm's daily returns during a given year. I have permno as identifier for each firm and daily data for stock return. Such as below. 

Permno           date                       ret 

10000         10/03/2002          0.005

10000         10/06/2002         0.0051

10002          12/06/2002         0.007

and so on. 

Could you please help me to calculate standard deviation of the firm's daily returns during a given year? 

Thanks in advance. 

[mkeintz]

If you want std of returns for each permno for the same year, then, assuming data are sorted by PERMNO:

proc summary data=have ;
  by permno ;
  where '01jan2022'd <= date <= '31dec2022'd;
  var ret;
  output out=want (drop=_:) std=retstd;
run;

If you want it for each year in a series of multiple years, then, if data are sorted by permno year: 

data need / view=need;
  set have;
  year=year(date);
run;

proc summary data=need ;
  by permno year;
  var ret;
  output out=want (drop=_:) std=retstd;
run;

[Fer_]

Thanks for your reply. 

I want to get yearly std for each firm (permno) which has daily stock return. Which means for each firm in each year, I need to have one std at the end. 

[mkeintz]

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@Fer_ wrote:

Thanks for your reply. 

I want to get yearly std for each firm (permno) which has daily stock return. Which means for each firm in each year, I need to have one std at the end. 

---

That is what my second code block provides.  Test it on a small sample of data to see for yourself.