6. Capital OneShares of Capital One ( COF) of McLean, Va., closed at $51.96 Thursday, returning 22% during the first quarter. Chris Brendler of Stifel Nicolaus told TheStreet that the company would be "one of the primary beneficiaries," during the first quarter, of ongoing improvements in credit quality. Data provided by SNL Financial shows the card industry continuing to improve, although it faces challenges as consumers cut their level of revolving debt. Loss rates for all six major lenders have declined over the past year, with February credit card master trust data showing that American Express ( AXP) continued to lead with the lowest annualized loss rate of 4.24% in February, followed by Capital One Financial 5.18%; Discover ( DFS), at 5.79%; JPMorgan Chase ( JPM), at 6.21%; Citigroup ( C) at 7.95%; and Bank of America ( BAC), with the worst loss rate of 8.85%. As discussed in greater detail in TheStreet's Credit Card Winners, Capital One is in the middle of the pack, in terms of credit card lenders' net portfolio yields. The net portfolio yield is the aggregate yield on a lender's card portfolio, less the annualized loss rate. Among the big six U.S. card lenders, American Express was in the lead with a net portfolio yield of 17.88% in February; followed by Discover Financial, in second place with a net portfolio yield of 17.49%. Bank of America was next, with a net portfolio of 15.10%; followed by Capital One at 13.39%, JPMorgan at 12.53%; and Citigroup, in last place, at 11.60%. Capital One is set to report first-quarter results on April 21, with a consensus earnings estimate of $1.48 a share. For all of 2011, the company is expected to earn $5.43 a share, followed by $5.46 a share in 2012. Out of 22 analysts covering Capital One, eight rate the shares a buy, 12 have neutral ratings and two analysts recommend investors sell the shares.