Estimate standard deviation quarter by quarter

[trungcva112]

@Peter_C
Your code works. Thank you very much. You are a life saver.
@mkeintz
Thank you. Your code gives me a STD of all firms' COGSQ in a given datadate (quarter). But I need a progressive STD of COGSQ of each firms when time passes.
But your code will surely be a useful reference for me in the furture.
@All

Thank you everyone

[Peter_C]

The DO loop could be extended to collect the min and max asset value or return, during the 'history to date'