VAR has other benefits as well. By now, all U.S. commercial banks monitor the VAR of their trading portfolios on a daily basis. Suppose a portfolio VAR suddenly increases by 50 percent. This could happen for a variety of reasons-market volatility could have increased overnight, a trader could be taking inordinate risks, or a number of desks could be positioned on the same side of a looming news announcement. More prosaically, a position could have been entered erroneously. Any of these factors should be cause for further investigation, which can be performed by reverse-engineering the final VAR number. Without it, there is no way an institution can get an estimate of its overall risk profile.