I’ve been watching shares in Discover Financial Services (NYSE:DFS) get crushed for the past week. Trading at the absurd p/e of 5.5, its been the victim of pessimism over plastic, an earnings report that comes late in the season and general trading malaise.

Just about everyone seems to think credit card companies are next in line for a crisis, but that doesn’t necessarily mean everyone’s right. Take the case of Ford Motor Company (NYSE:F), for instance. If you’d told me a year ago that they’d be trading at 4-1/2-year high, I’d say you were loony.

But, of course, that just means I missed out on a 494 percent surge in stock price over the past 12 months. See, when pessimism’s at its worst, it’s the time to buy, and right now, there are few other sectors besides credit card lending where pessimism’s still at high levels (real estate comes to mind and little else).

We’ll get a good barometer on credit card companies this week with the release of earnings from MasterCard (NYSE: MA) and Visa (NYSE: V). The two giant moons orbiting wallets across the country, the companies make their money off transaction fees. And just because people aren’t buying as much doesn’t mean they aren’t still paying fees.

As the world moves closer to a cashless society, Mastercard and Visa are perfectly poised to capitalize on the trend. And while they get all the attention, gems like Discover go unnoticed.

Discover Financial Services will report their earnings on March 18, 2010, before the market open.