If you are managing a portfolio and want to minimize risk, why is it mathematically beneficial to hold assets with a negative correlation to each other?

Portfolio risk is measured by the variance of the combined assets, which is the mathematical representation of how much the portfolio's total return fluctuates. When you combine two assets, the portfolio variance depends not only on the individual risk of each asset but also on the covariance, which measures how the assets move in relation to one another. Correlation is a standardized measure of this movement ranging from negative one to p....