# Portfolio correlation of a long-short portfolio

I have a portfolio of long/short positions in stocks. I would like to calculate the portfolio correlation. Should I somehow account for the short position while calculating the portfolio correlation? I am using formula a) from here.

Would be grateful for help!

If you follow the methodology on the page you point to, you will take these correlations into account because it will be in the sign of the weights $w_i$:
For instance, the first method: $$C := {2\sum_i \sum_{j> i} w_i \rho_{i,j} w_j \over 1 - \sum_i w_i^2}$$
1. Say $w_i=w_j=1/2$, $$C^+={1/4 \over 1 - 1/2}$$
2. And now say $w_i=-w_j=1/2$, $$C^-=-{1/4 \over 1 - 1/2}=-C^+$$