Commercial size of spending wallet (“CSoSW”) is the total business spend of a business including cash but excluding bartered items. Commercial share of wallet (“CSoW”) is the portion of the spending wallet that is captured by a particular financial company. A modeling approach utilizes various data sources to provide outputs that describe a company's spend capacity. Private equity firms and other investors of small businesses can use the CSoW/CSoSW modeling approach to more accurately evaluate small and privately held companies, both during investment and for evaluating prospective investments. Over-the-counter securities trading systems can also use this modeling approach to provide more accurate information and/or rankings of listed companies to their customers.