when it comes to investing pro forma latin for as a matter of form or for the sake of form generally refers to the manipulation or forecasting of financial results pro forma allows companies to exclude certain expenses and gains from their published gaap numbers and offer projections of future performance 
this can be useful for management and investors but also in some cases misleading to the untrained eye companies try to present themselves in the best way possible in financial statements to attract more investment and this can mean directing attention to pro forma numbers that paint it in a better light 