# How does the mean-variance model weight negatively correlated assets vs positively correlated ones?

Mainly wondering how the portfolio optimization model weights two stocks that have negative correlation, versus two stocks that have positive correlation. Does the mean-variance model weight them the same between these two scenarios, meaning it is blind to negative or positive correlation?

For example,

If stocks $$X$$ and $$Y$$ have a negative correlation of say $$\rho = - 0.4$$, what can be expected of the weights (their sign, or relative magnitude) the global minimum variance portfolio assigns to each if them in

1. a 2-asset portfolio, and
2. in a 3-asset portfolio shared with an uncorrelated/correlated asset $$C$$?

How do these answers change if instead $$\rho = +0.4$$ is positive?