Earnings for the financial sector kick into high gear this week with no less than Citigroup, Comerica, Bank of America, Goldman Sachs, US Bancorp, Morgan Stanley, Key Bank, BNY Mellon, Regions Financial and Citizens Financial all reporting results. We got a sneak peak of what this week's results could look like based on a handful of big players that reported last week.JPMorgan Chase, PNC Bank and BlackRock all beat both earnings and revenue estimates and saw their stock prices rise on Friday. BlackRock was the biggest riser, up more than 3%. Wells Fargo missed on revenue, but only saw its stock drop less than 1%.Banks are favorites to be outperformers in 2018, thanks to the potential for multiple interest rate hikes and stronger loan activity. The question now is whether or not the upside from those events is already priced in. Would you be a buyer of the banks/financial services companies heading into earnings later this week?