Portfolio standard deviation

In order to calculate portfolio volatility, you will need the covariance matrix, the portfolio weights, and knowledge of the transpose operation. The transpose of a numpy array can be calculated using the .T attribute. The np.dot() function is the dot-product of two arrays.

The formula for portfolio volatility is:

$$ \sigma_{Portfolio} = \sqrt{ w_T \cdot \Sigma \cdot w } $$

$ \sigma_{Portfolio} $: Portfolio volatility
$ \Sigma $: Covariance matrix of returns
w: Portfolio weights ($ w_T $ is transposed portfolio weights)
$ \cdot $ The dot-multiplication operator

portfolio_weights and cov_mat_annual are available in your workspace.

Calculate the portfolio volatility assuming you use the portfolio_weights by following the formula above.

Exercise

Portfolio standard deviation

Instructions