Commerce's Campbell has fund outpacing S&P 500.(Banking and Investments;)(Gary Campbell, chief investment officer of Commerce Bank N.A., St. Louis, MO)

When it comes to stockpicking, Commerce Bank's Gary Campbell is a number cruncher - bigtime.

In his nine years at Commerce, Campbell, chief investment officer of the Investment Management Group, has built a research effort that depends on in-depth quantitative analysis. To determine which stocks to buy and sell, the Commerce division uses computer models that generate trillions of calculations per month.

"We generate a massive amount of data to determine what are the important factors one should look at to determine whether or not a stock should be sold," Campbell said.

Based on computer platforms from a couple of vendors, the Commerce group has developed internal software that makes …