What goes up must come down, right? But what happens when those things do come down? Do they stay down forever, or is there a chance they, too, will go back up?

Contrarian investors bet that sometimes there's a bounce. Maybe even a big bounce.

First Bancorp (FBP 1.58%), a $12.8 billion bank headquartered in Santurce, Puerto Rico, is one of those stocks that went up, but then went down. Really, really far down, in fact. During the past 10 years, the company's stock is down 98%. During the past 12 months, it's down more than 35%.

Is this bank's abysmal run coming to an end? To find out, Motley Fool contributor Jay Jenkins is embarking on a three-part series analyzing the bank. In part one below, Jay uncovers the single and solitary reason that First Bancorp's stock has performed so poorly... its asset qualtiy.

Banking is a very unique business. When a typical company sells its product, that's the end of the transaction. For bank's like First Bancorp though, that's just the start. Management at First Bancorp must then get their product back -- that is to say, when the bank makes a loan, that loan must be repaid. If the loans don't get repaid, the bank will at best struggle. 

This is the essence of asset quality and the fundamental challenge facing First Bancorp. Loans have been made, and many are not being repaid. The key to this bank's turnaround is correcting this trend, and doing it fast.