NEW YORK ( TheStreet) -- While Citigroup ( C) investors pushed the shares down 5% to $4.86 in afternoon trading following a disappointing earnings release, the market reaction was simply another opportunity for investors to take advantage of a stock that is priced cheaply to forward earnings, giving the smart money a chance to make a long-term killing. While it's too early to know what effect Tuesday's earnings release will have on analysts' estimates, at Friday's market close Citigroup was trading at a low 9.3 times the consensus 2012 earnings estimate of 55 cents a share among analysts polled by Thomson Reuters. According to data supplied by SNL Financial for the 21 U.S. bank holding companies with market capitalization of at least $5 billion, only three had lower forward P/E's than Citigroup: Wells Fargo's ( WFC) forward P/E based on Friday's closing price of $32.75 the 2012 consensus earnings estimate of $3.59 a share was 9.1, JPMorgan's ( JPM) was 8.4 based on a closing price of $44.91 and 2012 earnings estimate of $5.35 a share and Bank of America ( BAC) had the lowest forward P/E of 7.5, based on Friday's close at $15.25 and the 2012 consensus earnings estimate of $2.02 a share. The most expensive among the large-cap banking group were Peoples United Financial ( PBCT), with shares closing at $14.42 Friday, or 19.2 times the 2012 consensus earnings estimate of 75 cents a share and Comerica ( CMA), whose shares closed at $42.25 Friday, or 14.6 times the 2012 earnings estimate of $2.90 a share. Comerica was down 8% Tuesday afternoon to $38.67 following the company's announcement of a deal to acquire Sterling Financial ( SBIB) and a fourth-quarter earnings beat with a large release of loan loss reserves. While it is a little early to be looking out further -- especially with continued uncertainty regarding legal reserves to be set aside for mortgage buybacks and all the coming regulatory battles as various provisions of the Dodd-Frank Wall Street Reform and Consumer Protection Act are implemented -- this uncertainty and the slow economic recovery have elongated the period in which long-term investors and build up their investments, adding on dips, for a big payoff a couple of years down the road. For the Big Four, the consensus is for earnings to increase at least 9% in 2013 from 2012.