How can I calculate portfolio standard deviation in Excel?

To calculate portfolio standard deviation in Excel, you can use the formula SQRT(SUMPRODUCT(COVARIANCEMATRIX, TRANSPOSE(WEIGHTS), WEIGHTS)), where COVARIANCEMATRIX is the range of covariance values, and WEIGHTS is the range of weights assigned to each asset in the portfolio. This formula takes into account the covariance between assets and their respective weights to determine the overall risk of the portfolio.