Rating downgrades are known to make subsequent downgrades more likely. We analyze the impact of this ?downward momentum? on credit portfolio risk. Using S&P ratings from 1996 to 2005, we estimate a transition matrix that is insensitive to and a second matrix that is sensitive to previous...

We use the financial crisis of 2007-2009 as a laboratory to examine the costs and benefits of teams versus single managers in asset management. We find that when a fund uses complex trading strategies involving the use of CDS team-managed funds outperform solo-managed funds. This may be due to...

Rating downgrades are known to make subsequent downgrades more likely. We analyze the impact of this 'downward momentum' on credit portfolio risk. Using S&P ratings from 1996 to 2005, we estimate a transition matrix that is insensitive to and a second matrix that is sensitive to previous...

We reassess the recent finding that no established portfolio strategy outperforms the naively diversified portfolio, 1/N, by developing a constrained minimum-variance portfolio strategy on a shrinkage theory based framework. Our results show that our constrained minimum-variance portfolio yields...

Minimum-variance portfolios, which ignore the mean and focus on the (co)variances of asset returns, outperform mean-variance approaches in out-of-sample tests. Despite these promising results, minimum-variance policies fail to deliver a superior performance compared with the simple 1/N rule. In...