portfolio-value-at-risk

Couldn't we combine the portfolio first to get the distribution of portfolio log returns and then calculate the portfolio VaR from there? Why do we need to compute individual VaRs and then combine them together using the var-covariance matrix?

Hi guys, For my (master) project I am trying to find the probability that a random variable, which is normally distributed, exceeds a quantile that is estimated by a limited number of observations. See attached for my attempt. - Is it correct? - How to incorporate the fact that the mean and...