Standard deviation of trailing values

[ivanpersie]

Hi there,

I am trying to compute the standard deviation of the trailing 12 months stock returns. What program code can i use? Thanks in advance for your help

[data_null__]

Do you have SAS/ETS software?

[ivanpersie]

Yes i have SAS  software

[PGStats]

SAS/ETS is a collection of tools for econometrics and time-series data processing and analysis. It includes PROC EXPAND, a procedure for transforming time series data in many ways, including your requirement for the standard deviation of a moving time window. - PG

[Astounding]

If you only have SAS, but not SAS/ETS, there are still ways to do this.

This forum has addressed how to calculate a moving sum (for the last 12 observations, for example).

You would also have to calculate the moving sum of the squared values, using similar techniques.

If you know SUM, SUM of the squared values, and N=12, you can calculate the standard deviation.

But it's easier of you have SAS/ETS.

[ivanpersie]

Please send me that link for calculating a moving sum