Estimate covariance matrix using a statistical factor model
covarianceMF(beta, stockM2, factorM2)(N x N) covariance matrix
(N x k) matrix of factor loadings (i.e. the betas) from a statistical factor model
vector of length N of the variance (2nd moment) of the model residuals (i.e. idiosyncratic variance of the stock)
(k x k) matrix of the covariance (2nd moment) of the factor realizations from a statistical factor model
This function estimates an (N x N) covariance matrix from a statistical factor model with k factors, where N is the number of assets.