How Banks Can Really Diversify Their Loan Portfolios
You can slice and dice your credit portfolio all you want, but if you are not paying attention to cross-correlations your efforts could be sub-optimal. For example, many banks separate their multifamily exposure away from their single family exposure. In some markets, these two subsectors are almost 80% correlated. A drop in housing prices usually occurs at the same time as a drop in multifamily values and in similar fashion delinquencies at banks usually move in lock-step.