Bank holding company (BHC) expansion into nonbank financial activities may increase or decrease the standard deviation of BHC ROA and/or the probability of bankruptcy of the BHC. Using individual firm data and a new application of a simulated merger methodology, I find the standard-deviation minimizing and bankruptcy-probability minimizing nonbank weights for a variety of nonbanking activities for two time periods, 1979-1986 and 1987-1997, for all BHCs and for large BHCs. I find that relatively substantial levels of investment in life insurance underwriting are optimal for reducing the standard deviation of BHC ROA. Appreciable levels of investment in life insurance underwriting, casualty insurance underwriting, and securities brokerage are optimal for reducing the probability of bankruptcy of the BHC.