"Conversely, "Mutascio added, "it is hard for us to envision further outperformance at these levels if economic growth remains sluggish -- leading to tepid revenue growth and EPS growth that is driven more by non-cash loan loss reserve releases than it is by pre-tax pre-provision income growth." There's no indication the U.S. economy may seeing a "breakout" from its estimated second-quarter GDP growth rate of 2.5%, and depending on the length of the government's shutdown, the fourth-quarter number could look ugly. For several years investors have been seeing bank earnings padded by a decline in loan loss reserves, as banks lower their quarterly provisions for loan losses. Major threats to third-quarter growth in pre-provision net income include major declines in mortgage revenue, as the refinancing boom subsides, with the biggest banks also expected to see a significant decline in trading revenue. Atlantic Equities analyst Richard Staite in a report on Sept. 23 estimated the eight large-cap U.S. banks he covers -- including Bank of America ( BAC), Citigroup ( C), Goldman Sachs ( GS), Morgan Stanley ( MS), PNC Financial Services Group ( PNC) and U.S. Bancorp ( USB), in addition to Wells Fargo and JPMorgan Chase -- would see third-quarter mortgage production revenue drop 45% sequentially and 55% year-over-year, with trading revenue declining 20% year-over-year.