We were visiting a hedge fund some years back when we had our first taste of the problem with mean-variance optimization—the tool advisors use to balance risk and reward in client portfolios. We ...

We had our first taste of the problem with mean-variance optimization at a hedge fund some years back. We loaded the positions into an optimizer, pressed the button, and discovered 25% of the ...

A set of assets is said to span the mean–variance space if the efficient frontier it generates cannot be improved upon with additional assets. Mean–variance spanning is used to determine empirically ...