Good luck chasing shares of Discover Financial Services (DFS). The stock, which has risen 22% over the past month, made multiple new 52-week highs last week and is showing no signs of slowing down.

Discover stock closed Friday at $68.41, up 0.19%. The stock is now up 27.58% year to date, compared with an 8.29% rise in the S&P 500 (SPX) index. Despite the sharp outperformance, exiting your Discover position could prove to be a costly mistake. The Riverwoods, Ill.-based company possesses three main qualities that suggest its stock still deserves a premium to the rest of the market. (See also: Assessing Discover Stock at 52-Week High.)

First and foremost, Discover continues to grow its loan balance. The company's total loans, comprising credit card loans, personal loans and private student loans, grew 5% year over year to $73.6 billion in the three months that ended September. For the full year, the company forecasts total loan growth to be in the range of 4% to 6% year over year. The higher its loan balance, the more money Discover will make on the expected interest rate increase in December. (See also: Fed Minutes Boost Chance of December Rate Hike.)

Secondly, the company's earnings, which have posted average growth of 6% in the past five years, continue to rise. Based on fiscal 2016 earnings per share estimates of $5.79, earnings are expected to rise almost 13% this year. This rate of growth should be strengthened by a healthy U.S. economy that is enjoying declining unemployment and an improving housing sector.

Lastly, Discover boasts a strong capital position. Not only does the company have more than $12 billion in cash on the balance sheet, it also has about $4.2 billion in operating cash flow. The strong capital position allowed Discover to hike its quarterly dividend by 7% to 30 cents per share. Combined with the company's new $2.5 billion stock buyback program, which should also help drive EPS higher, Discover is its investors' strongest ally. (See also: 3 Reasons Why Cash Might Be Obsolete in the Near Future.)

Want to learn how to invest?

Get a free 10 week email series that will teach you how to start investing.

Delivered twice a week, straight to your inbox.